v4 not using the new cache service

[juanjoi-empathy]

Using the last version of the actions/cache we have started to receive the following error:

Failed to save: Unable to reserve cache with key ....., another job may be creating this cache. More details: This legacy service is shutting down, effective April 15, 2025. Migrate to the new service ASAP. For more information: https://gh.io/gha-cache-sunset
Warning: Cache save failed.

The error references the already announced service deprecation. However, using @v4 according to the documentation (or even specifying the last 4.2.3 release), it must work with the new service API.
Is there anything to change/update to start using the new API?

Thanks in advance!

[RobertDeRose]

Similar issue, pinned to tag v4 and I and getting 422 from the service:

When attempting to save the cache, I get:

Failed to save: Unable to reserve cache with key 93fa68fe9dd436551cd506e3ea114524f8724348fba531a6157e72b89b8f9838, another job may be creating this cache. More details: This legacy service is shutting down, effective April 15, 2025. Migrate to the new service ASAP. For more information: https://gh.io/gha-cache-sunset

But there are no other jobs with this workflow.

When attempting to restore from cache, I get:

Warning: Failed to restore: Cache service responded with 422

updated

I checked, v4.2.3 and v4 both point to 5a3ec84.

In my action, it is pulling this she as well.
Download action repository 'actions/cache@v4' (SHA:5a3ec84eff668545956fd18022155c47e93e2684)

Yet, for some reason I am still get a legacy service warning

[ktrzcinx]

I have the problem too since April 17th, problem is on self hosted runners

Current runner version: '2.320.0'