MacBook Pro freezes when external monitor connected

I'm having the same issue with my 2021 macbook (M1Pro). All apps i've tested so far on the second monitor (in my case an LG UltraGear 34N76A) becomes randomly unresponding (frozen and no interactions are possible anymore for a few seconds).

During theses "freeze" moments, it's sometimes not possible to bring back the cursor on the mackbook's intergrated display.

I'm having this same problem, just in the past few days, with an external original Cinema display with its original adapter (DVI?) plus a USB-C to DVI adapter. This worked fine previously, though I'd occasionally have to crack open the MacBook lid and then close it again to wake up the monitor; now when I close the lid it completely freezes the external monitor (static image not responding to mouse or keyboard input) until I open the lid again, when all is normal.

Is the MacBook Pro screen freezing also or only the external monitor screen? You might need to Gera an adapter for thunderbolt 4 port.https://www.notebookcheck.net/Apple-s-new-2021-MacBook-Pro-only-comes-with-an-HDMI-2-0-port-which-cannot-output-4K-at-120Hz-on-an-external-display.574461.0.html

I am also having a similar issue. The windows freeze on occasion, and makes work unusable. It seems to display just fine, but scrolling through a webpage becomes extremely laggy. I have a USB C to Display Port adapter, with an older Apple Cinema Display. It’s unusable except to display static windows. But I can drag them back to the 14” display and interact normally.

PS—a reboot returns things to the normal condition, working fine on the cinema display with the MacBook Pro lid closed (2021 MacBook Pro M1 Max, macOS 12.3.1)