December Core Update or GA4 Issue?

Hi all - This is my first time tracking my traffic during a Google update and I feel a little flabbergasted and not sure what to make of things, so any insight is much appreciated! I'm going to use the day my traffic dove - December 13 - as the date for all of these stats. I do know that GA4 looks at different data than GSC but I'm not just comparing that. GA4: 25 sessions "anomaly detected", dropped from a consistent 200-300 sessions/day, has not recovered at all (actually worse on following days - like 5 sessions). GSC: 90 clicks, 5k impressions - took a bit of a dive, but has since recovered. Grow. me which tracks my Journey ads: 200 sessions, earned $8 that day. Has been steady since, and is only a slight dip from the previous month. I'm obviously happy about this as I'm on track to make another $200-250 for December. So I guess I'm just confused. GSC and Grow are tracking very similarly, and I've obviously had more than the 100 total sessions GA4 is claiming that I've had since 12/13 - otherwise Journey wouldn't be sending me money. If you saw something like this would you just ignore GA4 for now and try not to freak out? I did have a big jump in visits due to IG/FB sharing posts, but my core posts have continued to be the most visited, which are being found from Google. Any advice/ personal experience with this is much appreciated!