Sample button on Sampler window stops working

At times I’ve found the button “Sample” does nothing, sampling does not begin.

Workaround is to close and reopen the sampler window, choose the options you want and click “Sample” once again.

Trying to find steps to reproduce the problem reliably.

Screen recording

Also, related small thing.

When device is disconnected (eg. Uploading new game) then sampling stops (good) but the sample button still says “stop”, I think it should go back to “sampling”.