The testing branch doesn't solve the signing problem I was describing (problem 2):

I've compiled Armory with the testing branch (Linux mint 19).

I've documented the problem I've described in the following 8 sec video for the lockbox given above, when attempting to sign:

https://anonfiles.com/I9T0seh8b9/ArmoryVideo_mp4

• It is symetrical: it doesn't matter which 'Sign' button is pressed.
• Clicking the same 'Sign' button twice does nothing further.
• There is nothing in the log files.[/]