I can’t contribute much on this, but wanted to point out a couple of things which might be useful. In the log:
May 1 12:30:42 jetson-00-04-4b-cc-29-a9 NetworkManager: <info> [1619868642.9766] device (eth0): state change: unavailable -> disconnected (reason 'carrier-changed', sys-iface-state: 'managed')
If state changes to disconnected, carrier changed, then I tend to think maybe the physical interface has lost signal quality or did not respond in time. You might want to list the wiring from physical eth0 port to switch or router, etc., and consider altering this by changing what hardware the physical device connects to. An example of doing this is that if your Jetson connects directly to the router, then throw a switch in with only the Jetson on it, and then connect the switch to the router; or the reverse, if there is a switch between Jetson and router, then remove the switch temporarily and connect directly to the router. The key being that the physical wiring and signal quality should change. You might even try a different cable.
You might also mention if WiFi is in use. I say this because NetworkManager can cause wired ethernet to change as WiFi drops in or out. I doubt that’s a problem, but it is worth mentioning. Logs did not show WiFi/NetworkManager changes at the moments when wired dropped out, but it did mention NetworkManager as being associated with wired.