To me it unfortunately sounds like one of those rare base game issues as the freeze is on the strategic map, did you try to reload an earlier save to see if that helps ? You should save often, I do it every turn or so. Had such a freeze recently myself in TR and then the culprit was an AI hero becoming immortal and heard it may also occur if you play the game extremely long (200+ weeks).

I do save pretty often and I have 3 saves but they're all around the same time. Is there any way for this to be fixed? Id prefer not to restart my entire playthrough if possible.