SUMMARY

The panel can become unresponsive to hover events when hovering items while using a stylus. This issue happens on both X11 and Wayland, but it behaves differently in both sessions.

On X11, when window thumbnail tooltips appear, if you keep the cursor inside the panel and move around, the tooltip will stay open for a while (see BUG: 465650), but all other hover events will get "eaten" when )and after) that happens, including while hovering over other items on the panel, like when trying to show tooltips on the system tray.

On Wayland, hovering works fine until you interact with an application and come back (tested with Firefox (Xwayland) and Dolphin (native Wayland)). After you move back to the panel, nothing gets hovered anymore, and highlights of icons that were activated stay stuck until you use a normal mouse.

I will attach two videos, one for X11 and another for Wayland.

STEPS TO REPRODUCE
Wayland:
1. Open an application with a stylus, like Firefox
2. Interact with it with the stylus
3. Hover with the stylus over the panel, nothing will respond to hover. Clicking on the panel again with the stylus sometimes fixes the issue.

X11:
1. Hover over window thumbnails (if you can't reproduce, it helps if you click on the icon of an open app first with the stylus)
2. While still hovering the panel, move around (do not move the stylus outside of the panel!)

OBSERVED RESULT
Hover events are not respected on the panel, icons look stuck and no tooltips show up

EXPECTED RESULT
Should work the same way a mouse works

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.27.80
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8
Kernel Version: 5.19.0-32-generic (64-bit)
Graphics Platform: X11 (and Wayland)
Processors: 6 × Intel® Core™ i5-9400F CPU @ 2.90GHz
Memory: 15,6 GiB of RAM
Graphics Processor: AMD Radeon RX 570 Series