I thought I'd mention I had this issue. I never did figure out why it started happening, other than I got a wifi card so I could set the printer up so it could be used by other computers in the room.
I'd tweaked the bios for other unrelated issues before I installed the wifi card.
So I was installing a Thunderbolt 3 card, and having issues trying to get windows 10 to recognize the card, and eventually I bricked the computer. After I reset the BIOS, the Brother Printer no longer kept greying out.
Sorry it's such a vague description, but the point is that maybe just resetting your BIOS could solve your issue, if you know for certain it's not in it's default state. I know most people don't bother messing with the BIOS unless they have a need to, like I did. I used to have Satellite internet and it was terrible, and I had to get rid of IPv6 to get it work. When I reset the BIOS, it re-enabled IPv6, as far as the first reason I tweaked the BIOS.
I'd tweaked the bios for other unrelated issues before I installed the wifi card.
So I was installing a Thunderbolt 3 card, and having issues trying to get windows 10 to recognize the card, and eventually I bricked the computer. After I reset the BIOS, the Brother Printer no longer kept greying out.
Sorry it's such a vague description, but the point is that maybe just resetting your BIOS could solve your issue, if you know for certain it's not in it's default state. I know most people don't bother messing with the BIOS unless they have a need to, like I did. I used to have Satellite internet and it was terrible, and I had to get rid of IPv6 to get it work. When I reset the BIOS, it re-enabled IPv6, as far as the first reason I tweaked the BIOS.