Help please - Tiles wont refresh after a while

I have a device handler with tiles that change their state based on physical devices or by clicking the tiles.

I use sendEvent and everything works perfectly…until: a few hours later, if the app still shows the same device (and tiles) on the screen, then the state of the tiles won’t change on the screen -

in other words: if a switch tile shows “off” and I click it, it stays off. The code in the device handler is executed and the state actually does change to “on”. It just that on the screen the tile shows as “off”. If I go in the app to another screen and return to the virtual device then the tile will be “on”

Any ideas on how to refresh a virtual device screen?