Why these wouldn’t be cached is beyond me. Cool idea though!

It looks like that's just a generic error message. For me, this websocket message is received when the error appears:

    {"error":true,"body":"Your credit balance is too low to access the Anthropic API. Please go to Plans & Billing to upgrade or purchase credits.","done":false,"id":"XXXXXXXX","type":"cf_agent_use_chat_response"}

Wait long enough and it popped up for me. (Android, also basically Linux but using Vivaldi)

Took about 10 secs.

Same

(Firefox, Android (which is Linux))

Same.

(Firefox, Linux)