Lost 400-500 players in ultimate team and don’t know what to do

I was gonna go complete an sbc and noticed I was missing a lot of players. I then logged into the companion app to check amount of players in my club only to see it had decreased significantly by 400-500 players( I know it’s only players because I checked all the other items and everything was still there). What should I do now and who do I ask for help or support and can this stupid issue be fixed?