Here are the details:

# cat /etc/release

 DISTRIB_ID=Ubuntu DISTRIB_RELEASE=20.04 DISTRIB_CODENAME=focal DISTRIB_DESCRIPTION="Ubuntu 20.04.1 LTS" NAME="Ubuntu" VERSION="20.04.1 LTS (Focal Fossa)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 20.04.1 LTS" VERSION_ID="20.04" HOME_URL="" SUPPORT_URL="" BUG_REPORT_URL="" PRIVACY_POLICY_URL="" VERSION_CODENAME=focal UBUNTU_CODENAME=focal

# mysqld --version

 /usr/sbin/mysqld Ver 8.0.22-0ubuntu0.20.04.2 for Linux on x86_64 ((Ubuntu))

root@XXXXXXX:~# cat /etc/mysql/mysql.conf.d/mysqld.cnf | grep --color bind

bind-address = 0.0.0.0

Mysql Service Status:

root@XXXXXXX:~# systemctl status mysql.service
● mysql.service - MySQL Community Server Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled) Active: active (running) since Tue 2021-03-02 12:54:00 UTC; 1h 12min ago Process: 31460 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS) Main PID: 31484 (mysqld) Status: "Server is operational" Tasks: 40 (limit: 2372) Memory: 356.6M CGroup: / └─31484 /usr/sbin/mysqld
Mar 02 12:53:59 ip-192-168-1-115 systemd[1]: Starting MySQL Community Server...
Mar 02 12:54:00 ip-192-168-1-115 systemd[1]: Started MySQL Community Server.

root@XXXXXXX:~# tail -100 /var/log/mysql/mysql.log

/usr/sbin/mysqld, Version: 8.0.22-0ubuntu0.20.04.2 ((Ubuntu)). started with:
Tcp port: 3306 Unix socket: /var/run/mysqld/mysqld.sock
Time Id Command Argument
2021-03-02T12:53:51.185036Z 12 Query FLUSH PRIVILEGES
2021-03-02T12:53:54.040659Z 12 Quit

root@XXXXXXX:~# tail -25 /var/log/mysql/error.log

2021-03-02T11:48:38.852882Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-03-02T11:48:38.993865Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
2021-03-02T11:48:39.083889Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2021-03-02T11:48:39.084070Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2021-03-02T11:48:39.110064Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.22-0ubuntu0.20.04.2' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu).
2021-03-02T12:16:18.763905Z 137 [ERROR] [MY-013134] [Server] Table './flash@002dfast@002dprod@002ddb/videos' is marked as crashed and should be repaired
2021-03-02T12:16:18.765400Z 137 [Warning] [MY-010756] [Server] Checking table: './flash@002dfast@002dprod@002ddb/videos'
2021-03-02T12:38:29.704195Z 0 [System] [MY-013172] [Server] Received SHUTDOWN from user <via user signal>. Shutting down mysqld (Version: 8.0.22-0ubuntu0.20.04.2).
2021-03-02T12:38:31.195350Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.22-0ubuntu0.20.04.2) (Ubuntu).
2021-03-02T12:38:31.627975Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.22-0ubuntu0.20.04.2) starting as process 31217
2021-03-02T12:38:31.637190Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2021-03-02T12:38:31.975618Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-03-02T12:38:32.112947Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
2021-03-02T12:38:32.200447Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2021-03-02T12:38:32.200629Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2021-03-02T12:38:32.233977Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.22-0ubuntu0.20.04.2' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu).
2021-03-02T12:53:58.504425Z 0 [System] [MY-013172] [Server] Received SHUTDOWN from user <via user signal>. Shutting down mysqld (Version: 8.0.22-0ubuntu0.20.04.2).
2021-03-02T12:53:59.610387Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.22-0ubuntu0.20.04.2) (Ubuntu).
2021-03-02T12:54:00.048268Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.22-0ubuntu0.20.04.2) starting as process 31484
2021-03-02T12:54:00.058643Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2021-03-02T12:54:00.443835Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2021-03-02T12:54:00.581426Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
2021-03-02T12:54:00.665735Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2021-03-02T12:54:00.665956Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2021-03-02T12:54:00.693806Z 0 [System] [MY-010931] [Server] /usr/sbin/mysqld: ready for connections. Version: '8.0.22-0ubuntu0.20.04.2' socket: '/var/run/mysqld/mysqld.sock' port: 3306 (Ubuntu).

Error when trying to connect from another host which is hashed out as ABCXYZ:

root@ABCXYZ:~# mysql -u'phpmyadmin' -p -h192.168.1.115 -P3306
Enter password:
ERROR 2003 (HY000): Can't connect to MySQL server on '192.168.1.115' (110)
root@ABCXYZ:~#

Using exactly the same command from the mysql server (i.e. in this hashed out as XXXXXXX) & it works fine and we are able to connect:

root@XXXXXXX:~# mysql -u'phpmyadmin' -p -h192.168.1.115 -P3306

I also did packet capture on the "" to ensure that there is no connectivity issue from ""
root@ip-172-31-32-115:~# tcpdump -n host 192.168.1.188
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
12:43:19.631926 IP 192.168.1.188.47250 > 192.168.1.115.3306: Flags [S], seq 945902876, win 62727, options [mss 8961,sackOK,TS val 1425290709 ecr 0,nop,wscale 7], length 0
12:43:20.649648 IP 192.168.1.188.47250 > 192.168.1.115.3306: Flags [S], seq 945902876, win 62727, options [mss 8961,sackOK,TS val 1425291727 ecr 0,nop,wscale 7], length 0
12:43:22.665634 IP 192.168.1.188.47250 > 192.168.1.115.3306: Flags [S], seq 945902876, win 62727, options [mss 8961,sackOK,TS val 1425293743 ecr 0,nop,wscale 7], length 0
12:43:26.889674 IP 192.168.1.188.47250 > 192.168.1.115.3306: Flags [S], seq 945902876, win 62727, options [mss 8961,sackOK,TS val 1425297967 ecr 0,nop,wscale 7], length 0
12:43:35.081803 IP 192.168.1.188.47250 > 192.168.1.115.3306: Flags [S], seq 945902876, win 62727, options [mss 8961,sackOK,TS val 1425306159 ecr 0,nop,wscale 7], length 0
12:43:51.209876 IP 192.168.1.188.47250 > 192.168.1.115.3306: Flags [S], seq 945902876, win 62727, options [mss 8961,sackOK,TS val 1425322287 ecr 0,nop,wscale 7], length 0
^C
6 packets captured
6 packets received by filter
0 packets dropped by kernel

root@XXXXXXX:~# ufw status

Status: active
To Action From
-- ------ ----
Apache Full ALLOW Anywhere
3306 ALLOW 127.0.0.1
3306 ALLOW 192.168.1.106
22/tcp ALLOW Anywhere
3306/tcp ALLOW 192.168.1.106
Apache Full (v6) ALLOW Anywhere (v6)

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