Always Free A1 instance disabled without prior email notice — unable to resize or back up data

My VM.Standard.A1.Flex instance was recently disabled after the Always Free A1 resource allocation was reduced.

The instance is currently configured with 3 OCPUs and 23 GB RAM. I would like to reduce it to the current Always Free limit of 2 OCPUs and 12 GB RAM, but the instance is disabled and OCI does not allow me to change the shape.

When I try to edit the shape, I receive:

Instance is disabled and will not accept any action requests. Please contact customer support to reenable.

I did not receive any email notification or advance warning that the Always Free A1 allocation would be reduced or that my instance would be disabled. I only became aware of the change after the instance suddenly stopped, and while investigating the issue I found that some other users reported receiving advance notification emails.