I wrote about the trouble Celsius was in three weeks ago:
@rose98734/cryoto-lender-celsius-network-may-be-in-trouble
At the time I wrote the article they had $12bn in assets down from $24bn in December. I bet their assets are worth even less now, which is why they've halted withdrawals.
Their CEO has been spending a lot of time having fights with random people on twitter which is a sign he was under major stress.
It might be that crypto is simply incompatible with lending, because it is so volatile, and companies like Celsius were bound to fail.