vamp this would suggest a firmware issue, but so far you (and Mario77) are the only people reporting it.
Unfortunately there are 6 months of firmware changes between 8.2.3 and 8.2.4: Comparing 89a2371~1...3347884 · raspberrypi/firmware · GitHub
In order to determine which change is causing your random reboot, which is extremely rare (only two of you out of hundreds of thousands), you'll need to identify which firmware introduced the problem - although it seems more likely to be a hardware issue (maybe a marginal SOC) given how rare it is.
You could try testing the LE nightly builds from early this year to late last year, which covers the period for 8.2.3 to 8.2.4:
#0313: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0309: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0307: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0305: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0226: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0209: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0207: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0202: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0131: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0125: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0117: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0111: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0108: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#1201: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#1117: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#1103: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#1024: LibreELEC Testbuilds for RaspberryPi (Kodi 18.0)
#0313 is the most recent build you should test, and includes the same firmware that is used by 8.2.4 - in theory, you should experience random reboots.
#1024 is the oldest build you should test, and includes firmware from about the time of 8.2.3 - in theory, you should not experience random reboots.
If you test #1024 (and have no reboots) and then #0313 (and have reboots), then somewhere between those two builds you should be able to determine the build when the rebooting starts. Once we know this, we can identify what changed in the firmware.
Please continue testing with your 2.5A power supply.