Google AI Studio app production-breaking error with published Gemini API app

I am experiencing a production-breaking error with a published Gemini API app. I have documented the logs and am requesting a Google Meet call to screen-share and resolve this.

My app is designed for students to submit written work and the AI grades their work providing formative feedback based on set rubrics. Submissions are stored using the Firebase plugin. In the build and preview mode everything was working very well. However, since publishing the app so I could use it with teachers and students, every time I trial submitting written work I get one of two error messages (attached image). The other error message is an “AI forbidden” 403 error message about having a £0 cap. These error messages never appeared during build and preview before publishing. The error message about having a £0 cap is strange as my set cap is £5.

This is making the app unusable as it stands. Any advice would be greatly appreciated and even better, if I am able to receive a call from someone at Google so I can share my screen and troubleshoot, this would be incredible!

Thanks very much.