Team overall bugs

I need help, My squad overall was at 102 then I purchase a 105 overall player and the squad overall went up to 103. Then 2 minutes after it seems like a bug but my teams overall went back down to 102. Then I went again and purchase another player which is 104 overall and the teams overall went back up to 103 then go back down to 102. Why is this happening? And why can’t I sell back the players I purchased? It giving me the option to sell it but the button is grayed out I can’t click it. I need help !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ASAP