My Umbrel is back to running normal with an uptime of 9 days. It used to reboot daily. I didn’t change anything. And nothing was updated. 
Discussion
Are you running it on a Raspberry Pi?
Yes.
I have been running an Umbrel on a Raspberry Pi too, and it acts unstable at random moments like yours. I have seen others saying those problems stop if you choose someone stronger to run it in.
Yeah, nostr:npub1aeh2zw4elewy5682lxc6xnlqzjnxksq303gwu2npfaxd49vmde6qcq4nwx is reporting this as well.
If I could do it over, I would have just started on a standalone PC with a better processor and more RAM.
Makes sense, I eventually got frustrated and turned my old thinkpad into a start 9 node. My only complaint is that Start 9 doesn’t have Tailscale or WireGuard yet.
I had that problem on my old node, which was the main reason for the hardware upgrade. I think I was just running low on memory. Something was causing it to freeze up.
How is your uptime so far?
Almost 100% except for two days ago when the router it’s on went out and I rebooted before I realized what the problem was, and then LND decided to rescan every single UTXO, which took 5 hours. 😬
Thats great. Yeah, I wouldnt count that as it’s a different issue.
I switched from Primal address back to my Alby address, which sends zaps to my node. Maybe that was staining it somehow.
Backup🤙