If you live in a GDPR (or similar) applicable country you could try requesting all the data they have on you, that might include concrete reasons for suspensions.
If you have no legal way to force them to disclose things you're unlikely to ever get concrete reasons, as is pretty typical with these affairs.


Possible things that might have been actioned even when not actively using chat include search/adventurer plate comments, PF listings, character names, portraits (no really, though you'd have to put effort into that and would likely know exactly what did it) and gameplay (and that there is a right can of worms).