Some regexp rules do not work

[AdamWr]

Steps to reproduce

1. Add this rule to user rules:

/\/[0-9][0-9][0-9][0-9][0-9]/

2. Go to - https://example.org/
3. Open filtering log
4. Run in browser console:

fetch('/whatever/12345')

Actual behavior

Request is not blocked.

Screenshot

Expected behavior

Request should be blocked.
It's blocked if add rule like this:

/\/[0-9]{5}/

Screenshot

AdGuard for Windows version 7.11 nightly 24 (build 4097, CL 1.10.120)