Working on my Android 7.1 device. Steps to get it working:

 1. Download the adbd insecure version by leroy at https://nofile.io/f/86605d8qsJs/adbd-Insecure-v2.00.apk
 2. Install on your phone.
 3. Run `adb shell` in your adb directory
 4. Type `su` so u can get the "#"
 5. Type `setenforce 0`
 6. Enable insecure adbd. USB debugging turns off
 7. Turn USB debugging on and off from developer options
 8. Turn insecure adbd off and on again.

You can now adb pull into your PC.