This is kindof a niche issue, but I use the DVORAK keyboard layout and when I added keyboard shortcuts to the mouse buttons on my MX Master 2S they wouldn't work. If I switched back to the standard Qwerty layout they worked fine. This wasn't an issue while using the mouse on my Windows PC, but switching to my macbook is where this problem started. I realized the way to fix it is to record the keyboard shortcut while I have my computer in standard US Qwerty layout, then switch to Dvorak and the shortcuts work properly. If I record the same exact shortcut (for instance Cmd + C while in Dvorak and then try to use it, it doesn't map properly and triggers some seemingly random command. Might be something worth updating although I'm not sure how many people use alternate layouts.