fvwm and casting from chrome

Hi Everyone:

i have a frustrating issue with fvwm and casting from google's chrome, 
that maybe somebody has a workaround for.

Normally, under any other WM i've tried (and also on windows), in the 
chrome browser, choosing "Cast", will pop up a small window that asks 
the user what device to cast to. Unfortunately in fvwm that little 
window with those options does not show up.

I've tried both with my config, but also with a very fvwm config such as:
key c  A CM FvwmConsole
key r  A CM Restart
Key u  A CM Exec xterm

If anyone has a work around, that would be much appreciated, as casting, 
for better or worse, is very useful to me.

thanks!