Gitlab CI Container registry is suddenly failing ("unknown blob")

We have a repository which contains our custom Dockerfile. It's being build by Gitlab CI and published to the Container registry. The CI of our main project then uses it. It was all working fine and suddenly without changing anything all CI steps fail early because they can't seem to fetch the image:

For example: https://gitlab.com/ultrasonic/ultrasonic/-/jobs/4275744518

Running with gitlab-runner 15.9.0~beta.115.g598a7c91 (598a7c91)
  on blue-2.shared.runners-manager.gitlab.com/default XxUrkriX, system ID: s_90897a2659b5
  feature flags: FF_USE_IMPROVED_URL_MASKING:true
Resolving secrets 00:00
Preparing the "docker+machine" executor 00:06
Using Docker executor with image registry.gitlab.com/ultrasonic/ci-android:1.1.0 ...
Authenticating with credentials from job payload (GitLab Registry)
Pulling docker image registry.gitlab.com/ultrasonic/ci-android:1.1.0 ...
WARNING: Failed to pull image with policy "always": error pulling image configuration: unknown blob (manager.go:237:0s)
ERROR: Job failed: failed to pull image "registry.gitlab.com/ultrasonic/ci-android:1.1.0" with specified policies [always]: error pulling image configuration: unknown blob (manager.go:237:0s)