Changed network configuration, now HA can’t connect to MySQL

Configuration
1

I just finished rewiring out house and redoing the network infrastructure (new router, switch, etc). As part of the rebuild, I changed the network config from class C addressing to class A. Prior to the rebuild, HA (hass.io in docker on an Acer USFF pc) worked with MySQL on an external server flawlessly. After switching everything, HA can no longer connect to the DB server. The only thing that changed was the IP of the MySQL server, all other DB details remained as they were. I’ve verified that the DB info in the HA config is pointed to the correct IP, but it just won’t link.

The relevant messages in the error log are as follows:

(MySQLdb._exceptions.OperationalError) (2002, “Can’t connect to MySQL server on ‘10.0.0.75’ (115)”)
(Background on this error at: Error Messages — SQLAlchemy 2.0 Documentation) (retrying in 3 seconds)

Any ideas on what may be going on?

2

As quick verify maybe login MySQL db using HA user/pass from PC using same IP space as HA Server. Verify DB reachable and user/pass OK as start

EDIT
Do you have some “allow from” set in db or on network?

3

Other services using the same DB server can all connect, and I’ve verified that the HA user/pass work (as I mentioned, none of that changed in the network rebuild, all that changed was the IP scheme).

EDIT
The DB user is set to allowed from any host