Role is not stabilized

I'm trying to create a very simple role through CDK:

return new Role(this, "[REDACTED]", {
  assumedBy: new AccountRootPrincipal().grantPrincipal,
});

The role gets successfully created (I can see it in IAM console), but Cloudformation never reports its creation and throws a timeout after 30 minutes with the following message:

Role [REDACTED] is not stabilized.

All non-dependent resources are created successfully, and no further messages or errors are given. I've already tried to add a simple inline policy but it still doesn't work (role and policy appear on IAM console). Also, I've tried adding more non-dependent roles, and all of them report exactly the same error message (despite being used for LogGroup, Lambda, etc.).
I'm using the new eu-south-2 / Europe (Spain) / ZAZ region.

It's the first time I've encountered this error, and there are no results online besides a comment mentioning there were error rates and latency increases some time ago. However, this issue has been appearing for the entire day, so I'm not sure if it's temporary.