The knowledge base article for this property actually states that there might be a delay in these properties updating after an activity is logged. If you check back now, is it still out of sync?
"Last Activity" shown in Contacts list is not updating
SOLVE
Hey Phil, yes everything is back online and working properly. There was a lag of roughly 15-20 mins before the activity date would populate or update. So we are good to go, and thank you for the response.