If you still have LE 8.2.3, I would need a dmesg.
Somehow I should identify the wifi because it could easily be that you have a wifi chip that is missing from the image.
Okay, I'm investigating this because I don't know which wifi/bluetooth chip is in the MK808B+ device.
Thanks for looking into this, dtech!
If you need a hint, kszaq's MXQ 8.2.3.1 build has bluetooth working for the MK808B+. See RE: [8.2.3.1] LibreELEC 8.0 for S805