I have full access to chat? As far as i can tell. Are you sure you're switching to "Free chat" when finding a lobby? sounds like a bigger bug than what i've been having?
Are you playing on itch.io or using a Steam key obtained from here? Because the latter isn't where the problem lies. The itch.io version doesn't have access to accounts, which are required for free chat to be an option. Some people don't have access to Steam (for many reasons, some better than others, in my case, because Valve turned their game launcher into a literal health hazard 2 and a half years ago). If you buy a game on itch.io for the itch.io version and the itch.io version of the game doesn't work, the itch.io version should be removed and players who are considering puchasing it should be made more obviously aware that the itch.io version doesn't work.
EDIT: Unless they changed how it works without mentioning they did so in patch notes, which at this stage wouldn't surprise me. They promised to fix this problem with the itch.io version previously, then never added it to their roadmap in spite of promises and people refunding the game over its absence, and it hasn't been mentioned in patch notes that I've seen (because I've been keeping an eye out for that even though I have the game on EGS now anyway).
i gave my steam key to a friend long ago. i randomly started playing again maybe.. 3 weeks ago and I was able to LINK itch.io to amogus or something? it popped up a web browser and asked me to confirm. So i can use chat and everything just fine. but i had heard about itch account linking not even working. maybe i got lucky or they fixed it right before i started up playing again.