I have a Bolt with software version 21.11.1.v9 and pytivo desktop works fine.
I have had the "no tivos found" when I made the mistake of clicking on the
pyTivo Desktop shortcut instead of the
pyTivo shortcut when starting the program.
You should have two shortcuts in your start menu and you want to click on
pyTivo to start the program then once pyTivo is running you open
pyTivo Desktop either with start menu shortcut or right-click on pyTivo icon in taskbar.
So make sure you are clicking on
pyTivo when starting the program and not the
pyTivo Desktop shortcut.