SUMMARY
I tested a presentation on my laptop using KDE neon, LibreOffice Impress and KDE connect.
When I tested the presentation on my laptop, the laserpointer worked. When I connected the laptop to the beamer via an HDMI cable the laserpointer did not show up on the slides.

STEPS TO REPRODUCE
1. Run a presentation using LibreOffice Impress and KDE connect
2. Start the presentation in the presentation mode (only the slide is shown on the beamer, not your entire screen. Not sure how this mode is officially called)
3. Use the laser pointer

OBSERVED RESULT
The laserpointer is not shown on the slide on the beamer, but only on the slide on the laptop screen. So it's not like you don't see the laser pointer at all, but you only see it in the slide that is on the laptop screen.

EXPECTED RESULT
The laserpointer function's ring of death is also visible on the slide that is displayed by the beamer since this is the more important one.

SOFTWARE/OS VERSIONS
Operating System: KDE neon 5.24
KDE Plasma Version: 5.24.5
KDE Frameworks Version: 5.93.0
Qt Version: 5.15.3
Kernel Version: 5.13.0-41-generic (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 4800H with Radeon Graphics
Memory: 30.8 GiB of RAM
Graphics Processor: AMD RENOIR

Version: 7.3.3.2 / LibreOffice Community
Build ID: d1d0ea68f081ee2800a922cac8f79445e4603348
CPU threads: 16; OS: Linux 5.13; UI render: default; VCL: gtk3
Locale: de-AT (de_AT.UTF-8); UI: de-DE
Flatpak
Calc: threaded