Extremely slow scrolling after sleep mode

I have noticed for a while that, randomly, going from sleep mode causes scrolling to be ridiculously slow. It’s not that my scrolling setting gets ignored, but that the scrolling speed becomes less than a half of what the setting actually is.
Changing the setting doesn’t fix it. Setting the scroll speed setting to double that of my usual scroll speed to compensate means that, once this issue is fixed after a restart, that the scroll speed works normally again… and thus is too fast.
Happens on all windowed applications, including XWayland applications. Happened on both Nvidia and AMDGPU, if that’s relevant.

Any way to fix/prevent this bug?

Perhaps the setting is not correctly reloaded / interpreted.
Does changing the setting to something else and back to your preferred scroll speed setting and applying resolves the issue ?

That’s really weird, never experienced this.

What are your system versions kinfo ?

Does changing the setting to something else and back to your preferred scroll speed setting and applying resolves the issue ?

It sadly doesn’t, as mentioned in the original post.

What are your system versions kinfo ?

WARNING: radv is not a conformant Vulkan implementation, testing use only.
Operating System: CachyOS Linux 
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.18.2-3-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 9800X3D 8-Core Processor
Memory: 64 GiB of RAM (60.4 GiB usable)
Graphics Processor 1: AMD Radeon RX 9070 XT
Graphics Processor 2: AMD Ryzen 7 9800X3D 8-Core Processor

I also noticed what specifically happens: Normally my mouse scrolls around 4-5 times between each detent, however when this issue is active it scrolls only once. In other words, the scroll speed is the same, just how often it scrolls is reduced.

There is a fix that might be relevant here coming to Plasma 6.5.5: backends/wayland: fix the cursor hotspot with scaling (!8608) · Merge requests · Plasma / KWin · GitLab
Bug: https://bugs.kde.org/509516
But that’s a long shot.

That’s unfortunate. Gonna see if I can pinpoint what causes it further or if it gets solved eventually.

After more attempts of pinpointing this issue in logs and such, I weren’t able to find anything. Honestly, this issue may not be related to KDE Plasma at this point, so I’m marking this post as an answer and just use sleep mode less from this point.
Still, I wanted to measure how much the scrolling is malfunctioning. Only now did I get that bugged state again (mostly because I shut down my computer more often), hence the late post.

First, the between dedent scrolls (those between each dedent that make scrolling a page feel smoother) are reduced to once every two dedents when scrolling one at at time.
Weirdly though, scrolling a bit faster (one dedent every half second or faster) results in a between dedent scroll every dedent. I have no clue why.

Meanwhile, the on dedent scrolls (the ones that are registered as inputs in e.g. games) are reduced to one in every eight dedents, no matter how fast one scrolls.

In other words, it’s an 8x reduction. I know I previously said that doubling the scroll speed would be enough to fix the issue, but I probably misjudged how much “fast scrolling” is when compared to the very slow scrolling caused by this weird bug.

For your information, i have the same issue, also on cachy.

❯ kinfo
WARNING: radv is not a conformant Vulkan implementation, testing use only.
Operating System: CachyOS Linux
KDE Plasma Version: 6.5.5
KDE Frameworks Version: 6.22.0
Qt Version: 6.10.1
Kernel Version: 6.18.5-2-cachyos (64-bit)
Graphics Platform: Wayland
Processors: 24 × AMD Ryzen 9 5900X 12-Core Processor
Memory: 32 GiB of RAM (31.2 GiB usable)
Graphics Processor: AMD Radeon RX 9070 XT