“(MISSING)” in urls

Hi, I was wondering if, by any chance, the WordFence plugin ever replaces characters in a user’s requested url with “MISSING” (maybe to protect against XSS)?

I ask because recently in the WordFence live traffic logs, I’ve noticed a few bots visit this url:

/login/?redirect=http%!A(MISSING)%!F(MISSING)%!F(MISSING)ourdomain.org%!F(MISSING)wp-login.php

The “normal” version of that url, the one that humans and most bots hit is:
/login/?redirect=https%3A%2F%2Fourdomain.org%2F

Is the “MISSING” replacing something else, or are the bots really trying to visit a url with “MISSING” in the string???

And, maybe it’s a coincidence, but our site has briefly gone down on two occasions within a few minutes of being hit by the bots visiting the url with “(MISSING)” in it, and I’m trying to figure out what’s going on.

Thanks!