Have a look at the spin-up step to see the sha256 hash of the build that last worked. If this is different to the first failure, then you may be right. You can lock your image to that long hash (e.g. I have docker@sha256:5e74b427a55b7e257c7f9ebba1f7765fe13ea4535debec33a9ea08a69296b2bd) and see if that gets you going again.