Google AI Ultra plan is stuck on Starter Quota after I changed my domain

My Google AI Ultra subscription is fully paid and active, but I am still seeing the "This account is ineligible for higher rate limits through a Google AI plan at this time" error in Antigravity. This happened after I updated the account from a custom domain to a primary @gmail.com address. I have already tried clearing local cache files and verified that my region and age settings are correct, but the entitlement sync seems broken.

How I tried to fix the quota error

I spent a few hours trying to trigger the update manually since the billing side shows I am on the Ultra plan, but the API side is treating me like a free tier user.

1. Verified account identity and confirmed the transition from the custom domain to the @gmail.com address was successful.
2. Double-checked the Google One subscription status to ensure the Ultra plan was active and not in a grace period.
3. Cleared all local cache files to rule out a session token issue.
4. Confirmed the account region and age settings meet the requirements for Ultra access.

Despite this, the error persists: This account is ineligible for higher rate limits through a Google AI plan at this time.

The support loop problem

The most frustrating part is the lack of a clear path to a resolution. I contacted both support channels, and they are just pointing at each other. Google One support told me to reach out to Antigravity support, and then Antigravity support told me to go back to Google One.

It feels like a synchronization issue between the billing UID and the API entitlement system that only an engineer can fix with a manual trigger. If anyone here has a contact who can actually push an entitlement sync for a UID, or if you've found a workaround for the custom domain conversion bug, I'd love to know. Otherwise, I'm paying for a premium tier and getting starter limits.