Office 365 2016 Application keep turn to trial mode

I have one PC which having very weird issues at least 2 times in a month It turns to trail mode. The user is having Office 365 Business Premium license and his system installed with Office 2016 applications.

Whenever the above error occurs he has to signout his ID from office application and sign again. To me as a system admin, it is very annoying I can’t able to find a solution for this issue nor able to find the route cause.