Mouse Stuttinging/Lag after new GPU Installation (6700 XT)

Greetings all,

as the title suggests, I have some problems after installing my new RX 6700 XT and it drives me nuts.
I hope I am in the right subreddit and don't violate any rules. This is my first reddit post and I am out of ideas.
I have looked at different posts on reddit and on other forums but can't seem to find what I am looking for and what will solve my problems. Maybe you can help me with this.
I had no issues with my former GPU RTX 2060 Super at all and was looking forward to a little updade to the RX 6700 XT but since I installed it I am losing my mind.

Specs:
CPU: AMD Ryzen 7 3700X
GPU: AMD Radeon RX 6700 XT FE
Motherboard: MSI B550-A Pro
RAM: 32 GB DDR4
PSU: Seasonic Focus GX 650W
Operating System: Windows 11 24H2
WIRELESS MOUSE

Problem:
Sometimes the mouse seems to work just fine and smooth, but at other times it has an awful lag which makes operating the system or let alone gaming a nightmare. It does not seem to matter which application is open.
I have also noticed that my third monitor does not get a signal, but appears under display settings but only as 720p with no option to increase the resolution. Also the systems operates very weird and inconistent when the third monitor is plugged in.

Solving attemps:
- deinstalled all driver in safe mode via DDU for 6700 XT (6700 XT plugged in)
- deinstalled all driver in safe mode via DDU for 2060 Super (2060 Super plugged in)
- Windows 11 Update to 24H2 but it wasn't working on 24H2 either
- reinstalled the latest driver for 6700 XT via AMD Adrenaline
- checked all cables
- plugged the dongle of the wireless mouse into my work laptop and it was working smooth as butter

I read that there may be an issue with Windows 11 and AMD Radeon drives and that I should try using an older driver but I dont know which.
Also thought that my PSU might not be big enough but 650W should be sufficient.

Thanks in advance for your help!