Tasks lose "related to" field upon saving

Team, I’m on v8.2.1 hosted on IONOS. I’m noticing that upon saving tasks the “related to” field gets deleted. This is consistent on creating new records, and editing existing records. Is there a quick fix for this, or will a version upgrade resolve it? Thank you for your input!

Would you try it on the demo and report back if it fails the same way, with your step by step how to reproduce it.

Cannot reproduce in the demo, it works as it should. The demo is running v8.6. Maybe an update is in order here?

8.6 has a lot of fixes compared to your currently running version 8.2.1.
Maybe this is the one that fixes that issue.
I’d take a full backup, then upgrade to 8.6, and see if it’s resolved.