Unable to see remote device's screen

NH-Cobra

I am unable to see the remote devices screen after connecting like I used to.

I can upload files etc.. but cannot remotely do anything on their desktop.

I help support a few elderly relatives and I used to be able to see what they see and walk them thru doing things but after upgrading Teamviewer on my computer and on some of their devices I no longer see their screens.

I am Running Windows 10 on my laptop with Teamviewer 15.2 version.

Most of them have Android Tablets running Quicksupport Ver 14.2

Any suggestions to get access to their screens again ?