I have updated BTT just now and since the update my shortcut CMD + Mouse button 3 / 4 doesn't work properly. I have set it up to go page back/forth in the browser and it does, but opens the website in new card instead of current one. It works well with Option key, so I'll use that in the meanwhile, but i'd prefer it worked as before
Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
Logitech MX Vertical + Apple Magic Keyboard 2
Ah, BTT has recently switched to use the native trackpad back/forward swipe events for page back / forward (because they work in all apps in macOS), unfortunately Chrome does open a new tab when executing these swipe events while holding CMD.
As a workaround you could setup separate actions for Chrome and use the "Trigger Menubar Menu Item" action to trigger History;Back or History;Forward