Edit: Never mind, the problem was my wifi router was in the same room, causing interferences.

Using the same device in same location I’ve had 8 - 22MB/s, with the smaller speed I had a warning about high interference

Hello there, thank you for reaching out and I am sorry to read and to know that you are having issues with the Quick transfer feature of the DJI Mini 2. For us to be able to assist you further, may I know what is the duration and file format of the files we are transferring? In addition, were there any error messages or warnings showing on the DJI Fly app? Thank you.

Make sure the phone and drone are away from high interference areas to get the best results at around 20 mb/s. I transferred four-minute, 4K video in about a minute this morning.

DJI Gamora Posted at 2020-11-21 07:31
Hello there, thank you for reaching out and I am sorry to read and to know that you are having issues with the Quick transfer feature of the DJI Mini 2. For us to be able to assist you further, may I know what is the duration and file format of the files we are transferring? In addition, were there any error messages or warnings showing on the DJI Fly app? Thank you.

Other’s have encountered this in as noted in other forums.  It appears the fix is to kill the DJI app and relaunch it.  In other words, it’s not a real interference problem.

Regardless of location I always get the High Interference warning even when there are no power lines, wifi nets etc.

In the kitchen i get 24mb/s, my router is down the hall but I have a Mesh setup so I actually have a dish in the kitchen
I also have many, many wifi, zigbee and z-wave devices that should cause interference but the QT seems to manage ok
Out in the field when about 30m away from the ac i get about 5mb/s but that's understandable and it was just a test anyway