The Next/React issue seems to be solved.
I was able to resolve my issue. Gemini did hallucinate creating a file. Which I realized by trying using it a few times, in conjunction with c-p the error log into it, and then I read the error log and the code. So, I created it.
It seems the changes Gemini brought to the website created an error that was hidden by the CVE. Firebase Studio stopped publications while I was doing changes on the website. It was confusing. I assumed it was still the CVE, because I made very superficial requests to Gemini.
Thank you @jhuleatt and Firebase Support. They were very helpful when they reached out and brought me out of the idea that the issue was React/Next by suggesting to look at the logs.