v4.0.0.2 on Windows 11 64-bit.
Going batty since I can't post an open parentheses here, so the file name is on the left of this image:
https://imgur.com/a/CQ7htyx
If you type the full email address in the file name into Replace, and then type joe@b into With, the New Name preview loses the open parentheses, but the actual rename function will include it in the renamed file.
This file name is how Microsoft instructed us to name Outlook signatures for the desktop version, BTW.
Hopefully that's clear enough to recreate.