Hybrid Video. Either no HDMI or No Browser hardware acceleration

Laptop has hybrid Nvidia + Intel video cards setup.
Hybrid nvidia driver installed and working.

When HDMI monitor is connected - it is not identified. Though it used to work before.
Forcing nvidia with

emvycontrol -s nvidia
enables HDMI monitor connection and identification. Both external and internal work fine. If it is switched back to hybrid - external monitor stops working.

But in nvidia only mode now browser hardware acceleration stops working for every browser available in repositories. And what is super strange is that for another user on the same laptop - acceleration works at the same time.
So it’s either hybrid mode: monitor doesn’t work, browser hardware acceleration works fine.

Or Nvidia only mode: monitor works but hardware acceleration stops working in one particular account (other accounts have it).

Can’t find the logic in this situation. Please advise.