Mouse button is interpreted as tab, cannot create trigger

Hi, love BTT, happy customer. Lately I've re-installed BTT and now the side button on my Logitech M720 mouse, button 5 normally, is being remapped by BTT as the tab key. This is a brand-new configuration and there are no triggers configured at all for any device. I have cleared the config from the library multiple times and the alpha build does not fix this. I cannot explicitly create a trigger for this button because the button click is interpreted as a tab which moves focus to the next element.

I'm not sure how to debug this, or if there is some kind of event viewer I can look at.

Intel Macbook Pro
macOS 12.6
BTT 3.904

EDIT: based on the keyboard shortcut capture, button 5 is being specifically interpreted as ctrl-option-tab.

Did you maybe configure that via the logitec software at some point? (The behavior will then be saved on the mouse)

I haven't got the logitech software installed, and the behavior stops when I quit BTT, so I assumed the issue was there.

if it’s configured in BTT it’s either in the „normal mouse“ section, or in the keyboard shortcuts section.

Could you post screenshots of these?

This is very odd, the behavior has reverted. Mouse 5 now registers as ctrl+up, which is its previous behavior. Nothing else has changed, I did not reboot. Here are the screenshots:

Is it possible for one button of the mouse to be interpreted as a keyboard key press?

Never mind, I'm now convinced this isn't an issue with BTT. Appreciate your time and thanks again for helping.