Pi-hole is running on a Raspberry Pi B+ with the latest version of Raspberry Pi OS. There were no unusual events during installation or while it was running. I was able to monitor the activity on my iMac with Safari, using the latest versions of the software. The Pi-hole sits on a simple home LAN with all direct cabling, not WiFi.
However, 3 times the unit stopped working and would no longer boot. I did a complete reinstallation of Raspberry Pi OS and the Pi-hole software. It worked for a while, then repeated the annoying crash.
There is no debug information available