MySQL logging is not working in paper spigot v1.19.4, and this is happening on 2 completely different servers. We have also tried a brand new server running Paper version git-Paper-492 with only 3 plugins installed including CoreProtect, EssentialsX, and EssentialsSpawn and we ran into the same issue. We even tried a server running MC 1.19.3 and MySQL logging worked perfectly but as soon as we upgraded the server to 1.19.4, it stopped working again.

[18:18:50 INFO]: Checking version, please wait...
[18:18:51 INFO]: This server is running Paper version git-Paper-492 (MC: 1.19.4) (Implementing API version 1.19.4-R0.1-SNAPSHOT) (Git: 497b919)
You are 2 version(s) behind
Download the new version at: https://papermc.io/downloads
Previous version: git-Paper-384 (MC: 1.19.3)

[18:18:53 INFO]: Server Plugins (3):
[18:18:53 INFO]: Bukkit Plugins:
[18:18:53 INFO]: - CoreProtect, Essentials, EssentialsSpawn

[18:18:56 INFO]: [Essentials] CONSOLE issued server command: /ess version
[18:18:56 INFO]: Server version: 1.19.4-R0.1-SNAPSHOT git-Paper-492 (MC: 1.19.4)
[18:18:56 INFO]: Brand version: Paper
[18:18:56 INFO]: EssentialsX version: 2.20.0-dev+51-c52c1fe
[18:18:56 INFO]: EssentialsXSpawn version: 2.20.0-dev+51-c52c1fe
[18:18:56 INFO]: Economy Layer: None
[18:18:56 INFO]: Vault is not installed. Chat and permissions may not work.
[18:18:56 INFO]: Fetching version information...
[18:18:56 INFO]: You're 1 EssentialsX dev build(s) out of date!
[18:18:56 INFO]: Download it here: https://essentialsx.net/downloads.html

[18:19:00 INFO]: ----- CoreProtect -----
[18:19:00 INFO]: Version: CoreProtect Edge v22.0-dev1.
[18:19:00 INFO]: License: Valid donation key. (########)
[18:19:00 INFO]: Database: Using MySQL. (Initial DB: 21.3)
[18:19:00 INFO]: Consumer: 2 items in queue.
[18:19:00 INFO]: Discord: www.coreprotect.net/discord/
[18:19:00 INFO]: Patreon: www.patreon.com/coreprotect/

It seems to be MySQL 5.6 that's the issue. Managed to recreate in testing using a fresh ubuntu 22.04 VM.

wget https://downloads.mysql.com/archives/get/p/23/file/mysql-server_5.6.51-1debian9_amd64.deb-bundle.tar
tar xvf mysql-server_5.6.51-1debian9_amd64.deb-bundle.tar
sudo dpkg -i *.deb
sudo apt --fix-broken install

Connects to the mysql database fine, but silently fails to save anything.

[09:54:02 INFO]: [net.coreprotect.hikari.HikariDataSource] HikariPool-1 - Starting...
[09:54:02 INFO]: [net.coreprotect.hikari.HikariDataSource] HikariPool-1 - Start completed.
[09:54:02 INFO]: [CoreProtect] CoreProtect has been successfully enabled! 
[09:54:02 INFO]: [CoreProtect] Using MySQL for data storage.
[09:54:02 INFO]: --------------------
[09:54:02 INFO]: [CoreProtect] Enjoy CoreProtect? Join our Discord!
[09:54:02 INFO]: [CoreProtect] Discord: www.coreprotect.net/discord/
[09:54:02 INFO]: --------------------
[09:54:03 INFO]: Running delayed init tasks
[09:54:03 INFO]: Done (2.328s)! For help, type "help"
[09:54:03 INFO]: Timings Reset
[09:54:27 INFO]: UUID of player self_slaughter is ebef591e-4bac-4ffc-bd8c-f08a584ac3bd
[09:54:27 INFO]: self_slaughter joined the game
[09:54:27 INFO]: self_slaughter[/192.168.202.1:51033] logged in with entity id 288 at ([world]-69.21651340807256, 63.0, 283.5087243716616)
[09:54:35 INFO]: self_slaughter issued server command: /co l u:self_slaughter t:5m
[09:54:40 INFO]: self_slaughter issued server command: /co l u:self_slaughter t:5m
[09:59:43 INFO]: self_slaughter issued server command: /co l u:self_slaughter t:5m
[09:59:45 INFO]: self_slaughter lost connection: Disconnected
[09:59:45 INFO]: self_slaughter left the game
> stop
[09:59:49 INFO]: Stopping the server
[09:59:49 INFO]: Stopping server
[09:59:49 INFO]: [CoreProtect] Disabling CoreProtect v21.3
[09:59:49 INFO]: [CoreProtect] Finishing up data logging. Please wait...
[09:59:59 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:00:29 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:00:59 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:01:29 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:01:59 INFO]: [CoreProtect] 1,211 items left to log. Please wait...

It seems to be MySQL 5.6 that's the issue. Managed to recreate in testing using a fresh ubuntu 22.04 VM.

wget https://downloads.mysql.com/archives/get/p/23/file/mysql-server_5.6.51-1debian9_amd64.deb-bundle.tar
tar xvf mysql-server_5.6.51-1debian9_amd64.deb-bundle.tar
sudo dpkg -i *.deb
sudo apt --fix-broken install

Connects to the mysql database fine, but silently fails to save anything.

[09:54:02 INFO]: [net.coreprotect.hikari.HikariDataSource] HikariPool-1 - Starting...
[09:54:02 INFO]: [net.coreprotect.hikari.HikariDataSource] HikariPool-1 - Start completed.
[09:54:02 INFO]: [CoreProtect] CoreProtect has been successfully enabled! 
[09:54:02 INFO]: [CoreProtect] Using MySQL for data storage.
[09:54:02 INFO]: --------------------
[09:54:02 INFO]: [CoreProtect] Enjoy CoreProtect? Join our Discord!
[09:54:02 INFO]: [CoreProtect] Discord: www.coreprotect.net/discord/
[09:54:02 INFO]: --------------------
[09:54:03 INFO]: Running delayed init tasks
[09:54:03 INFO]: Done (2.328s)! For help, type "help"
[09:54:03 INFO]: Timings Reset
[09:54:27 INFO]: UUID of player self_slaughter is ebef591e-4bac-4ffc-bd8c-f08a584ac3bd
[09:54:27 INFO]: self_slaughter joined the game
[09:54:27 INFO]: self_slaughter[/192.168.202.1:51033] logged in with entity id 288 at ([world]-69.21651340807256, 63.0, 283.5087243716616)
[09:54:35 INFO]: self_slaughter issued server command: /co l u:self_slaughter t:5m
[09:54:40 INFO]: self_slaughter issued server command: /co l u:self_slaughter t:5m
[09:59:43 INFO]: self_slaughter issued server command: /co l u:self_slaughter t:5m
[09:59:45 INFO]: self_slaughter lost connection: Disconnected
[09:59:45 INFO]: self_slaughter left the game
> stop
[09:59:49 INFO]: Stopping the server
[09:59:49 INFO]: Stopping server
[09:59:49 INFO]: [CoreProtect] Disabling CoreProtect v21.3
[09:59:49 INFO]: [CoreProtect] Finishing up data logging. Please wait...
[09:59:59 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:00:29 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:00:59 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:01:29 INFO]: [CoreProtect] 1,211 items left to log. Please wait...
[10:01:59 INFO]: [CoreProtect] 1,211 items left to log. Please wait...

Thank you. This was exactly the problem.