IssueTracker

At present, the advertised base priority can only be configured on a per BGP session basis, not a per-prefix basis for routes advertised in that BGP session.

https://cloud.google.com/sdk/gcloud/reference/compute/routers/add-bgp-peer#--advertised-route-priority

It's worth mentioning here that Feature requests have no ETAs or guarantees of implementation.The product engineering team will verify the feasibility of the request and will take decision accordingly. We will post further updates regarding this feature request on this thread.

PS :
I've tried restarting the VM, purging cache, using other browsers...
No luck.
The issue usually ends with this error.

It is currently working for me

and now its not working anymore