I have a Pixel XL that works with no issues in combination with the RC but I have a lot of trouble when I try to connect directly to the phone. Most attempts fail then occasionally it works so I wonder if there is a particular order to follow when connecting?
Here is what I do currently.
Start the Got app and choose the wifi connection method.
Turn on the MA then hold the rear button until 2 beeps sound.
Connect the phone to the MA wifi.
Return to the Go4 app but it usually just sits there and does not complete the connection.
Occasionally I get it to connect so perhaps I do a different sequence, not sure.
I always make sure that other apps like Litchi etc force stopped first.
Any suggestions?

Our apologies for the inconvenience. May I know what is the android, firmware and DJI Go 4 App version you are using? Kindly refer on the attachment below on how to properly link your mobile device to your aircraft directly.

My phone is on Android 9, the MA and the RC are using the latest firmware and the Go4 app is 4.3.0

Well the new version (4.3.2)  of DJI Go4 solved my connection problem !