The subscription I bought to sync the apps last worked on 4/18/22 and hasn't worked anymore. I had not requested help because I thought it was not active but checking I found that on 2/Sept./22 I was billed for the renewal and in Google Play it appears that it will automatically renew in Sept. from 2023 which means that it has remained active all this time but when I try to synchronize the account, I get a synchronization error.
What error exactly? Both subscriptions are valid and linked to you email firstname.lastname@example.org. Check sync setup in the app settings, especially account name. Try to setup sync again (click "Unlink account" button).