Hi, would you have a look at Primatte Studio in Vegas 20, any media type.
When 1st applied it seems to work but is a bit unpredictable
then if - Preset - Reset to Defaults it becomes pretty much unresponsive 
Thanks.
( seems to works perfect in AE)
Hi Gid,
I just checked it in Vegas 20 on Win 10 with the current beta build and it appears to be working as intended on my system. I followed your steps exactly but can’t repro your experience. Could it perhaps be related to a cache issue in Vegas?
Cheers,
P.
Thanks, apart from the Ctrl+Shift on the launch icon I don’t think Vegas has a cache? I’ll get back to you,
Did this, no change.
Someone else posted on the Vegas forum & when I tried it it was weird …
There was a problem a little while ago with a Vegas update, 5th April-ish, nobody could open Vegas without disabling the internet, Vegas issued a patch fairly quickly - Build 403, did you have to go through that?
I’ve cleaned Vegas as much as poss, did the cache thing in the pics above, deleted everything from C:\Users\User\AppData\Local\VEGAS Pro\20.0
This boring 8min vid shows a video & a colour chart png, sometimes it would pick the colour, sometimes not, (I put pink behind then it’s obvious what if anything is getting removed)
& I tried it on just a green screen, it did pick the green, second time.
This is green selected but nothing,
I could share exactly the same pic with no effect but Green screen chosen in FX Browser,
I understand if it’s working at your end there’s no a lot you can do 
