I am experiencing the same problem. Started yesterday (20/11/2023) - would register PC searches but would not register mobile searches or the bonus for using the Edge browser. Did all the usual steps (clear cache/cookies/browsing history and reinstalling Edge and Bing), no change.
Cut forward to this morning (21/11/2023) and it started register mobile searches up to 57/60 points, then stopped. During this time, it only registered 3 of the searches as the bonus for using the Edge browser (and yes, Edge was used for all 19 searches for the mobile search points).
Seeing as everyone seems to have started having this issue at the same time, this looks more an more like a MS problem.