Lately I have been getting a lot of these:

Especially on one repo where the pipeline spins up 4 parallel steps.
We are running self-hosted bitbucket pipeline runners on a kubernetes cluster.
I already set up docker proxy cache and perform docker logins whenever I can.
But the images in question seem to be the bitbucket images hosted on ECR:
public.ecr.aws/o4g5y6x4/sox/atlassian/public/pipelines-auth-proxy:prod-stable, etc.
Is there any way to avoid/mitigate this issue?
It does not seem possible to use a registry mirror for images not hosted on docker-hub.
Am I somehow not caching these images properly with my k8s setup?
Any help would be greatly appreciated.