dGPU port performance issues

Which Linux distro are you using?
Fedora

Which release version?
40

Which kernel are you using?
6.11.4-201.fc40

Which BIOS version are you using?
3.03

Which Framework Laptop 16 model are you using? (AMD Ryzen™ 7040 Series)
AMD Ryzen™ 7040 Series

I recently got the 7700S Graphics Module and I’m having an issue with poor performance out of the dGPU’s USB-C port with Gnome using Wayland. If I connect a 7620x2160 120hz monitor using either a DisplayPort → USB-C cable or a Display Port → DisplayPort Expansion Card, the display is detected properly and can be set to 120hz, but the desktop is very choppy.

I tried running glxgears and it seems to be locked at about 39 fps. Any games I tried would also cap out at 40 fps (with DRI_PRIME=1 or dGPU being set in game). nvtop did show the dGPU being used.

I tried lowering the resolution to 4k 120hz and glxgears locked at 60 fps. I also tried with a 1440p 144hz monitor and performance on it seemed to fluctuate quite a bit between 115 fps and 144 fps.

If I move the cable to one of the side ports, everything would be smooth and glxgears would be locked at the refresh rate and games would run smoothly using the dGPU.

I put Windows 11 on a USB just to check and there the dGPU port performance was fine. I also tested the Fedora 40 live usb and performance was slightly better (60 fps instead of 40).

I also tried Fedora’s KDE spin, which had better (still not as good as the iGPU ports) dGPU port performance, but ran into games freezing and crashes, so I went back to Gnome.

Any ideas? I would like to use this to run another monitor.