False notification of remote computer status?

IT novice would appreciate help with this issue...

I use freeTeam Viewer for remotely assisting an elderly relative. It works great but there is one thing that concerns me: I receive false Team Viewer notifications that my relative is online when she isn't.

This has happened a few times over the past couple of months. Once, her 'phone + broadband service was down for several days yet I still received such an 'online' notification during that period.

I use Team Viewer version 14.7.1965. Not sure what version my relative uses.

Would really appreciate a jargon-free reply, thanks. I don't even know if I've chosen the correct board (whatever that is) to place this enquiry.