Mouse wheel stuck scrolling sideways in Steam client

[Sergeant Major DeathTickles]

So this happened WHILE I was in the Steam client: I was browsing mods and apparently hit just the right combination of buttons and suddenly my mouse scroll wheel will only scroll sideways, which means most of the time it just doesn't do anything. My cursor now has a little scroll wheel icon next to it with two arrows on the sides, so it's clearly not a bug but the trouble is I have NO IDEA how to turn it off. This only affects the steam client, and if I click on something on my other monitor like my browser, THEN I can scroll up and down in steam but as soon as I click back into it, that icon comes back and I can't scroll.

I've restarted my computer, reinstalled Steam, I have no 4D mouse wheel option on my computer that I can find, I tried plugging in a different mouse, deleting and reinstalling the mouse driver, nothing has worked and what little I've found online has not helped.

My mouse is a Sharkoon Fireglider.