Thank you for your reply! I realized that after deleting them that the backslashes were actually meant to be there in the database….Oops!
I have now stopped deleting them, hopefully it won’t cause any issues for the ones that are deleted.
The problem with backslash is ongoing. After re-adding that code, it seems to be a little less, though it could just be part of the randomness of it.
The activity I refer to is just the standard activity on the /activity page. Seemingly at random, the filters do not apply and the backslash is visible on the front end for some posts. Currently now it’s only happening for update posts and posts on other person’s wall.
As such, not sure how to go about troubleshooting this.