I have an issue that the HereLink unit crashes and reboots the moment I connect another QGC on a Win10 laptop via UDP. I use RTSP as well as MavLink, the MavLink id of the laptop is 254.
I also have the impression that the HereLink unit has extreme problems to connect to the router as long as QGC is running on the laptop.
I get the impression that the issue is connected to the more recent versions of QGC running on the laptop. A version I installed on a clients laptop in early 2021 runs without problems, the version I installed a little bit later causes issues.
Can you try to reflash the firmware on Herelink controller, and see if the problem still exist?
Are you using hotspot from Herelink? or connecting your Herelink and laptop to same wifi network?
I can try this in some months when the unit is in service. But I have the issue on several units, so I think it is unlikely that it is a issue which can be solved by reflashing.
What I can see is that the issue does not seem to happen with customers who use older QGC Windows versions.