They I understand it: There was a deal to ban TikTok unless ownership changes --- the original intention was no Chinese involvement, but now it seems "ownership change" means the ownership is amicable to the current president. There was also something of a grace period for when that ban went into effect if TikTok could show they were actively in the process of finding a new owner. The current president basically just kept insisting that grace period was in effect while he constructed a bid for ownership that aligned with his and his friends (business) interests.

Basically, Congress did not do its job and ignored the very law they voted for.