MacBook AIR 2015 "F" keys not working. Pls read! Tried all!

HHHHHEEEEEEEELLLLLLLLLLPPPPPP!!!  Yes, I am desperate!!!

ALLLLLLL the answers treat a TOTALLY DIFFERENT issue (which is just a setting problem, much easier resolved and treated in several threads). Do not confuse please! No, my problem is not the same.

F functions DON’T WORK. I mean REALLY DON’T WORK, they don’t respond even after reseating SMC (yes I did this!!!), even after checking “Use all F1, F2, etc. keys as standard function keys” box, even after checking and unchecking everything related to keyboard. Even after reinstalling, actually several times, even after reinstalling an older OSX (10.10). PLS DON’T GIVE THIS ANSWERS/ADVICES!

Before answering, considering a duplicate or “reassigning” the thread to another one pls check if THERE IS A REALY DIFFERENT ISSUE! AND IT IS!!!

I need someone that encountered this issue THAT I DESCRIBE, not the easier one, that can and was resolved by the above solutions.

DESCRIPTION:

 In Catalina, touching any F key would not do anything but a sound, same as the one when you click an wrong kew. One of the F keys change something, not at all important or correct.

There is a chance that someone replaced the keyboard with a BUT there is also a possibility of a “wrong re-assigning driver” [MAYBE] when updating to Catalina. I saw other people that didn’t change the physical keyboard, they just updated and the OSX “lost” it’s ability to recognize the F keys.

Some external Apple keyboards work well (ex aluminium wireless one and wired “wide” aluminium one); others don’t work, like the white/transparent older one) - of course I am talking about the F keys.

From my [quasi-educated] guess, it’s a problem with the keyboard driver. Moreover, I had the problem in Windows (yes, although there are huge differences with OSX, there are similitudes too). So, once the OS wrongly identified the driver as “the right one” it’s quasi-impossible to make it move on, even to replace it manually there are  hidden folder, writing permissions etc etc.  I presume this could happen with the THIS IS ONLY ONE of the hypothesis, for people that have a clear understating of files and folders of the OSX might find this hypotesys interesting …or not.

If yes, the answer might be “ Go in this folder, modify this and save it (after you made a back-up of the unmodified file etc)”

PS: I see this for years already! You need hours and hours to solve an issue because the forums are flooded with "Did you try restarting?" ; "Uncheck this or that", "Reset SMC [ link]”. I don't say this is not useful… but read the question completely! Then... if your knowledge are limited and "you're just trying to help" --- Thank you from all my heart.... but pls let "the scene" to people with deeper knowledge.

 THE VERY “CORE” OF PROBLEM SOLVING IS LOST AMONG DOZENS OF "TRY THIS, TRY THAT ETC". Everybody giving advice. What about 2 or 3 answers from skilled technicians or even software engineers saying: "First restart, then check uncheck, then try SMC reset then, if didn’t;t work…. YOU HAVE A REAL PROBLEM…. AND YOU HAVE TO…………………… OH THANKS GOD!!! Be the “Thanks God” man not the “Did you try restarting” man.

PPS: I saw this in Windows too: once Windows is wrongly assign a driver to a specific device, it is very hard to convince “him” to “give up” that driver and  it will not accept another driver.

So, a possible solution is to find out where OSX Catalina keeps the drivers, identify the keyboard driver, erase it (after making a back-up on desktop and saving the location), then force an update or even better - isolate the driver from another Macbook and copy paste it). Anybody  have this kind of knowledge? I [almost] have it in Windows... (need one more night of research and a laptop that “worth it”). To put it short: restated, checking/ unchecking boxes, reseted SMC and PRAM, reinstalling etc etc etc DIDN’T WORK.