I'm working with BTT 3.202 on MacOS 10.15.1. My keyboard and mouse are from the Logitech G-series and use a separate application, Logitech Gaming Software, to perform various customizations, including programming extra, non-standard keyboard and mouse buttons.
This morning I tried to set that LGS software to call the MacOS application switcher (Apple key + tab) at the click of a mouse button. My hope was to call the switcher and then select an application with my mouse. However, there was not a way within LGS to mimick the behavior of pressing Apple + Tab, and then releasing Tab while still holding Apple. This keeps the window open but does not trigger cycling through applications.
I then opened BTT to see if that application switcher could be called with a custom keyboard shortcut that I would then map to the desired mouse button using LGS. BTT is capable of calling the application switcher as I want it, using the shortcut I made there, I can open the window and make selection with the mouse.
When I try to map that keyboard shortcut to the mouse button in LGS, however, things start to get wonky. LGS, for some reason, registers any letter button press with modifier keys as a Tab. So if my keyboard shortcut in BTT is set to Ctrl + Shift + L, LGS sees this as Ctrl + Shift + Tab. This behavior only occurs while BTT is running, when I quit, LGS behaves normally. The keyboard shortcut works perfectly without involving LGS.
Anyone have any idea how to further troubleshoot or investigate this, or any possible workarounds? I'm hesitant to call this a BTT bug as it does involve another notoriously buggy piece of software, and again, the keyboard shortcut works as desired when you remove LGS from the equation.