I'll have to play with the button controller a little to see if I can replicate using a virtual. In the mean time, I made a small change to the Dimmer code to use an interpretation of the ST Child Button instead of the Hubitat Virtual Button.
To use it you'll also need to add the child driver at:
https://raw.githubusercontent.com/thebearmay/hubitat/main/development/stChildButton.groovy
Edit:Hold off for a minute... Found a bug.
