Are you sure you replaced both the files I attached before (
MBP8,1 Airdrop Catalina.zip) without "Merge" but selecting "
Replace All", a better method would be if you remove first your IO80211Family*.kext and then copy mine patched, because if you merged they won't work properly.
There is a lot of difference between "Merge" and "Replace" a file/folder in OSX, when you handle patched kext or framework they must be Replaced.
After applied my patched files, do you have in your Catalina Finder the AirDrop menu correctly showed ?
If so you need to plug a Bluetooth 4.0 usb dongle (also a PC one) to your Macbookpro8,1
because for AirDropping with the latest iOS 13 (or 12) a Bluetooth 4.0 authorization from the Catalina Mac is mandatory!
Moreover the MBP8,1 is particular because apple assigned to it two different board-ids:
Mac-50619A408DB004DA and
Mac-94245B3640C91C81
while instead typically the board-id are common to almost all of the same machine model shipped from factory.