Update to core-2021.3.0 fails with bad gateway

The new update to 2021.3 fails. After the snapshot, the update just stops. Disabling the snapshot results in a bad gateway:

image

My system is nothing special, nothing highly customized, running supervisor-2021.03.3 on a Raspbery PI 4. There is nothing else running on this machine.

Hi, i had/have the same issue twice now because my home assistant just crashes. made a new SD-card with a fresh install put back my snapshot try’ed to udate the core and again same failure and again a HA crash not able to start up or reach the UI even after 1 hour.

The problem repeats itself with core-2021.3.1 and core-2021.3.2. To update, I keep trying and restarting the server while disabling the snapshot. Eventually, it works somehow. However, this leaves a bad taste. Never had this before the 2021-3 version.