My API sometimes works, sometimes not on cloudflare tunnel

What is the name of the domain?

example.com

What is the issue you’re encountering

Basically I set a demo computer at home and installed cloudflare there to access it remotely, I expose some Get API to it and trying to test it via a Excel VBA macro program. Here is the thing, sometimes the API is actually works, and sometimes not, I don’t know why, might be a configuration problem on my cloudflare? if so, how can I solve it? I am new to cloudflare, thank you guys.