does 'xset(1) dpms 20' activate xidle(1) after 20sec?

Hello,

does 'xset(1) dpms 20' activate xidle(1) after 20 seconds?

How to repeat:

$ xset dpms 20
$ xidle -timeout 180 &

With this I am locked out after 20 seconds, not 180.

I looked hard to make sure everything runs with default settings.

Just saying, maybe someone has time to reproduce.

Marcus