Property designation disappeared

After going through all of my imported transactions for 2020 and assigning all rents and expenses to their respective properties I ran a few reports, one of these reports was from September 15 to December 31 of 2020. When I ran this report it was missing about 80% of the transactions but what happened was that these transactions had lost their property designation and it seems I have to start from scratch assigning all of these transactions to their respective properties one by one again…wtf? Has this happened to anyone else? please help!! just spent hours doing this now I have to do it all over ?