After many months of Bluetooth problems trying to use my Magic Trackpad (old style) and Magic Keyboard on my new Mac mini 2018, my Bluetooth and WIFI problems are gone. I had to use my wired mouse and keyboard and wired internet to think about using any of my equipment to do anything. My setup is a Catalina 10.15.5 Mac mini with 3.2 GHz 6-core intel Core i7, 32 GB 2667 MHz DDR4 connected to two 42"LG HD TVs using TV 1 with HDMI connector and TV2 with a USC-c to HDMI cable. Also connected at the same time are two/or three Scan Disk extreme 1 T SSD drives, Roland GO
iano USB, Yamaha MG 10XU mixer USB and sometimes I use a eCpu Razer Core X with a Gigabyte RT 5700 XT (to use my airplane simulator or apple games). I have been reading this thread for months and trying everything with no solutions to my Bluetooth cutting on and off problems. As you can tell, I am using all of my Mac mini output ports. Before finding my solution, I did purchase two shielded USB cables to run my a USB hub four feet away to run all my musical USB equipment, but did not change any problems encountered. I had resigned myself to using no WIFI or Bluetooth so I could do my music and games. By accident I rearranged my desktop to make things look nicer. The two LG TVs are to the back of the desk, one wall mounted and the other on the right angled with desk feet. To save space I stood the Mac mini on its side, power switch up, outputs facing the front of the desk and the round bottom facing me in back of the angled TV. There is six inches of space under the angled TV, so I can see the Mac mini. Everything started working. I have since moved my USB piano and USB mixer back to the desk in front of me. No more issues with Bluetooth keyboard or Magic Mouse. I can use WIFI or wired internet in any combination to the computer or two monitors. In fact, I can now put my MacBook Air in front of me using any of the wifi, USB or Bluetooth connections. Here is my final proof. If I lay the Mac mini down (round bottom on the wooden desk), my Bluetooth goes crazy. I have tried all directions lying down. As soon as I stand the Mac mini up with the round bottom facing the room. Everything works fine. I did try to place the Mac mini standing on its side with the outputs in other directions, but with so many times I need access it is most handy for the outputs to be accessible. I am a retired Sea Captain with very limited electronic education. I have tried every combination of ideas and now it works with everything within three feet of the computer as long as it is on its side with the circle facing me (looking at it from under the angled TV. Sorry for the long explanation. I wanted to cover all the details for all of you technical people. Hope this gives some idea to resolve anyones problem.