SUMMARY
When booting up, either with the lid open or closed, plasma doesn't remember the previous settings of the external display. It always defaults to 1680x1050 with 100% scaling and 59.88Hz. Even if I change the resolution back to 1920x1080 the screen doesn't reflect the change, everything still looks blurry.

Another peculiar behaviour that happens is that when I boot up with the lid open, the system takes longer to load for some reason. With the lid is closed while booting up, it loads much faster.

Another weird behaviour is that, sometimes, when I resume from sleep, the Panel simply disappears. When that happens I have to go to settings and change the resolution or scaling and then the Panel appears again. 

Yet another weird behaviour is that, when I open the lid while the laptop is running the external screen defaults to 1680x1050 with a weird scaling 0.6667% (see attachments). Then when I close the lid it defaults back to 1920x1080 but with a scaling of 0.6667%.

This was tested when I mirror both screens.

STEPS TO REPRODUCE
1. Boot the laptop with the HDMI cable plugged in (either with the lid closed or open);
2. Closing or opening the lid;
3. Resuming from sleep

OBSERVED RESULT
Plasma doesn't remember the external screen settings and sets the resolution to 1680x1050 with a scaling of 0.6667%. The same behaviour is also true when resuming from sleep.

EXPECTED RESULT
The resolution and scaling should remain the same when booting up the laptop with the lid either closed or open. When closing or opening the lid while the system is running. When resuming from sleep.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: KDE Linux
KDE Plasma Version: 6.5.80
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.0
Kernel: 6.17.8-arch1-1 (64-bits)
Wayland

ADDITIONAL INFORMATION
This is not a KDE Linux problem, it happens with other distributions as well (Fedora 43 or Kubuntu). It's a long running issue that happened with other plasma or framework versions, and other kernel versions.

The laptop in question is an MSI Summit E16 (A12UCT model) with a dedicated HDMI port. It has a i7 1280p CPU with two GPUs Iris Xe + Nvidia rtx 3050.