Instance stuck in STARTING state and unable to stop

My compute instance has been stuck in the STARTING state for an extended period.
I am unable to stop, reboot, reset or terminate.
This started after an attempted shape resize from VM.Standard.A1.Flex 4 OCPU / 24 GB RAM to 2 OCPU / 12 GB RAM
The work request ocid1.coreservicesworkrequest.oc1.eu-marseille-1.abwxeljrrhxi6nfjk5vy
failed with:
InternalError - A problem occurred while starting the instance. Please retry or contact support at https://support.oracle.com.

Instance OCID:
ocid1.instance.oc1.eu-marseille-1.anwxeljrn5wrz

Could you please help unlock the instance and restore it to a stable state.
Thank you.

Update:

I cannot terminate and recreate the instance as a normal recovery path.