[G3 Q&A, Help & Troubleshooting] dyliho:
Hey buddy I found myself in the same boat as you and a few of these other peeps in the Q&A with the issues concerning WiFi. The 3xception is that mine occured after frolicking mindlessly in Hidden Menu land galavanting about with no concern as to what the hell I was changing, bolstered by an almost psychotic illusion that what I was doing would somehow enhance my connectivity with the possible addition of a kinetic-energy based super power.

Seriously though - I did eventually retrace and undo almost all of what I originally did (mostly just checked or unchecked the many boxes in the IMS and related settings) and got my gps, bluetooth, and wifi to turn on and scan. However - I had already lost (never had) IMEI, (my phone was a purchase off Amazon that was bojangled from the get go - perma-locked and such) So I used the CRC MID wizard and rewrote my addresses and IMEI. It was there I noticed my country stuff was @ open_eu and I am in America - dont know if that really matters but didnt really look into it because I was on the other mission of righting my wrongs. Somewhere in all of this my adb.boot deleted (I noticed the toast when trying to enter modem protocol settings and one or two others) and so I believe that may have been why I was not able to boot into twrp but to boot up regularly(?) temporarily at least because after putting it down and walking away to ponder on it earlier this morning I used flashify to try and restore a nand of a stock debloated 20f rom, and well, we have seen where this was going all along....

Fastboot mode started is my lone response from my D850 save for the ability to enter hardware control mode (where it does show the IMEI took hold the CRC wizard wrote, so I assume the WiFi address and BT addy inscribed with it would be fairly legit. I took that leap thinking maybe they should all be established at the same time. I know many of you are shaking your heads and yeah I get it, I knew not to touch shiz so in essence I knew what I was doing - jackin it up...)

I know that was a clusterbomb there but having taken a little while to reflect on how insanely stupid all of the stuff I did was, especially so very extremely and freaking ignorantly at the same time all without making my usual notes, I am now ready to climb back on that horse and resurrect her from fastboot mode. Which looks pretty damn right up a dark alley as far as how much I know to do... Heres to XDA as that lone streetlight at the end of that dark alley for all the morons like me!

So what I was wondering is are you O.G. wifi mac and bt addy intact o are you having the issues I and a few others are where it was showing 02:00:000:00 or whatev? And just an advisement (which we all usually mostly follow, right? :p) to record and back up your original settings/files/etc. and do whatever it is one at a time - I am cometely anxious and beast mode on this problem so maybe if we all friggin collaborate and get some documenting what does and doesnt work a decent and legit fix can be found and a guide written....

And speaking of after this I am making a guide to the acronyms you come across in Hidden Menu land... I will post any help I come across and hopefully a few people get energized and amped up to tackle this gnarly beast. Lets go XDA troops!!!