I have tried to reproduce it in my test environment but didn't notice the same issue as you are having.
You could try followings to resolve this issue:
a) Clear cache and cookies [1].
b) Browse in private with Incognito mode [2].
c) Try different browsers.
If this issue's root case is the browser then this might be helpful.
Are you getting this error following specific steps? If so, could you share those steps? With this information in hand, I would be able to verify the issue and report internally if needed.
However, it seems this issue is related to your project only, and this platform is Google’s official bug reporting and feature request platform that affecting multiple users.
For this reason, I would suggest followings:
1) If you have tech support, open a case with Google Cloud Platform support [3]
2) If you like, you could also open an issue with GCP community support. For this ServerFault would be appropriate platform [4]
[1]
https://support.google.com/accounts/answer/32050?hl=en
[2]
https://support.google.com/chrome/answer/95464?co=GENIE.Platform%3DDesktop&hl=en
[3]
https://cloud.google.com/support/
[4]
https://serverfault.com/