Fennec seems to automatically request gitlab's cookies

Steps to reproduce：

1. Do not access gitlab or clear all cookies directly.
2. Use the Cookie AutoDelete extension to clean up cookies.
3. It is prompted that gitlab's cookies have been cleared.
4. Repeat the above steps with Mull-Fenix ​​for the same extension list. There will be no prompt for the third step.

I want to find out why this behavior occurs.