OK so up until recently ive been using gemini api cuz its free and I dont have money to buy or gets credits for a paid quality api. But I regularly switch between 2.5 flash and 3 flash preview, so tell me why when I switch or use gemini 2.5 flash I get cucked from chatting and gives me either a prohibited content error or this new error ive never seen before.

PROXY ERROR 400: Please ensure that single turn requests end with a user role or the role field is empty. (unk)

Idk what this means or how to fix it so if any of yalls got suggestions or ideas pls hit me up and comment 🙂‍↕️ please and thank you.