I just checked the github page and it seems this bug is low priority:
Memmy does sometimes not let you post or comment due to a weird bug that thinks you‘re posting in the wrong language.
I just want to point out that I‘ve had this bug twice so far and others (maybe many) will have it too which severely hinders the growth of lemmy at this critical time.
If someone reads this who has any clout, stuff like this is what can trip a promising platform like this. Exponential growth and all.
Have a good one.
/u/sunaurus@lemm.ee is on it.