My two cents.... Take a minute and write out on a whiteboard the areas/components others have mentioned to check. Once it has been checked, write down some notes on what you found and cross it off the list. Once you have completed the list, review your notes and reach out for further clarification on your findings if needed. It is easy to get side tracked when hunting an issue or trying to figure out WTF just happened, so the whiteboard list and corresponding notes may help keep you on track and prevent inadvertently skipping over something. Truly hope you are able to find a simple/inexpensive reason why this occurred. I read your whole thread and the other WIX nightmare thread...the WIX that was on my 1991 is now in the trash, replaced with an OEM filter. Likely it was good to go but for less than $4, it was a no brainer to swap it out.