"Unable to check for update"

Since yesterday I am trying to update my Umbrel to 0.4.8. What could be the issue here?

Ok so the problem might be related to having Pi Hole running as my DNS server.
What is the best way to whitelist Umbrel ?

stop pihole, update, start pihole. Done

No, Pi-Hole is not the Problem for this particular error.

The HTTP 500 error code shows that the server is reachable but has a problem which was not handled.

My Umbrel currently shows the same error:

manager | Error getting available update: getaddrinfo EAI_AGAIN api.umbrel.com
manager | Unable to check for update
manager | /v1/system/get-update
manager | NodeError: Unable to check for update
manager | at Object.getAvailableUpdate (/app/logic/system.js:167:15)
manager | at processTicksAndRejections (internal/process/task_queues.js:97:5)
manager | ::ffff: - - [Sat, 21 Jan 2023 23:10:02 GMT] “GET /v1/system/get-update HTTP/1.0” 500 28 “-” “Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.2 Safari/605.1.15”
manager |

To me it looks like there is a problem with the umbrel server!
Or this is the normal behavior when no update was found. Not sure about this.