please check
STR
0) set up CP (latest version, PaperMC 1.20.2, Java 21) with full logging for events

1. SET GLOBAL general_log = 'ON'; (Debian 12, MariaDB)
2. full log of this empty queries, connection number of this empty queries assigned to CP queries, huge log per sec:
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   INSERT INTO co_block...
   INSERT INTO co_chat...
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT
   START TRANSACTION
   COMMIT

as result,
on MySQL sever in SHOW /*!50002 GLOBAL */ STATUS LIKE 'Com_%';
we see "commit" in the top of list in "Average per second".