Question [1.18.2] Low Server TPS

[Ben2445Fun]

We recently updated our Server.Pro server to Paper 1.18.2 (from Paper 1.18.1) and have been receiving low server tps since. As an uneducated player in anything debug-related, I was hoping someone would be able to shed some light on what might be causing the tps drop.

Info:
In 1.18.1, 7 people would still yield 20 tps.
In 1.18.2, 3 people will start to lower tps.
Ignore anything Worldedit or AsyncWorldEdit (AWE), unless it's causing majority lag.
Multiple custom datapacks & command block chains are running.

 

[Tau]

Try creating a new paper server with 100% stock settings and getting 3 people on it.
If that still has the same problem it's likely the host. If it doesn't you know it's a misconfiguration.

In the latter case try adding back your server settings ie: properties, start flags paper & spigot.yml etc, and see if the issue is still there.
If it isn't continue adding things such as worlds and then move onto plugins.

I have a suspicion it is to do with Vanilla Scheduled tasks in your world ie: command blocks, scripts etc