Feedback Builds made with 2019.1 not working properly on dual monitors (cloned)

I already posted this in the general forum, but this is way too crowded to get noticed.
I'm not sure this is the right place.

This bug happens on builds made with 2019.1 on every machine I could have tested.

I updated my game project recently from 2018.3 to 2019.1.

I noticed that when I hooked up a secondary monitor to my laptop (HDMI), and set it as clone display, the builds made with 2019.1 were limited to 30 fps and pretty unstable (buggy sound, slow down, freezes ...).

I could reproduce this in an empty project with default settings.

This was working properly in 2018.3. I'm using a TV, on a daily basis, as a secondary monitor to test my game.
I'm wondering how this hasn't been noticed already.

bug report : 1147620

 

It happens only on Windows 10 systems.
It worked fine on version 2018.3.

 

And it occurs in full screen mode only.