When I placed a Soulwood sign down for decoration it closed the client (no crash report) and once I was able to log back into the server, the sign was invisible.

Version 1.18.2-1.4

hm, that's. Really odd. It not rendering is technically intentional since it normally crashes anytime it renders for whatever reason.
Can you send me latest.log ?

latest.log

I hope this is the correct one? I'm very new to this, sorry!

You're fine :) Thank u for bringing up the issue

Sadly I can't help much seeing as you're having problems with the 1.16.5 version of the mod.