Motorola Droid 4 won't sync with Office365 when not on wifi

[AC Question]

Hi, I know this is old phone, Motorola Droid 4 Version 4.1.2 but just recently it will only sync emails when on wifi. If its using 3G/4G it says it can not connect to server. The "Restrict Background Data" is NOT checked and the certs are good. No one else has a problem in the company, just the two people with these phones. Any suggestions are appreciated.