I have long lived with an old computer (a laptop with 2 extra monitors) on which I have used the old Sony Vegas 10 for sporadic video editing. It has actually worked well. But now I got myself a new laptop and I still use the extra monitors I have from before... And I chose to get myself some newer software. So i upgraded to MAGIX Vegas Pro 22 Suite. And now when I try to use preview on an extra monitor it does not work. I have the little laptop to the left (monitor 1) one a bit bigger monitor right in front of me (monitor 2) and an identical one to the right (monitor 3). I run Vegas on the middle one and when I set the right one to be the extra preview monitor the preview opens up kind of in the middle between monitor 2 and 3. The left side of the preview image cover half of monitor 2 and the right side half of monitor 3... If I instead set the preview to be shown on monitor 1 (the laptop screen) it places itself correctly on that screen but the playback is not smooth. It flickers (blinking) insanely.

Anyone got any idea of why and what I can do to fix this issue?

Hardware:
HP Pavilion Plus 14
Windows 11 Home
Intel® Core™ Ultra 7 - 155H
32GB RAM
1TB SSD
Intel® Arc™-graphic

+ two Philips 272E1CA/00 monitors.
One connected via HDMI and the other one via an HDMI>USBC-adapter.