Pointer is always scrolling sideways (Not a mouse issue!)

Hi friends!

Here's a perplexing one. Once in a while, my Macbook (16 inch 2019, running MacOS 10.15.7) decides I need to start scrolling pages to the left. And then, wherever my pointer is, it scrolls that window to the left. It doesn't matter which application I'm in -- if the application will scroll to the left, it scrolls to the left. The only fix is to restart my computer, and the problem has kept coming back.

Here's what I've tried to fix it:

• Turning off my wireless mouse, because I thought maybe some dust had gotten in there and interfered with the sensor. Nope. Problem persists when the wireless mouse (Logitech) is totally unplugged.
• Uninstalling Better Touch Tool (No luck there either)
• Thinking maybe it was a trackpad issue, I went into the Accessibility settings and told it to ignore the trackpad when my wireless mouse is plugged in. That did what it was supposed to do (trackpad was indeed ignored) but did not solve my scrolling problem.
• I have an external monitor plugged in, so I tried unplugging that because honestly why not try everything?
• I tried running some terminal commands:

launchctl stop com.apple.Dock.agent
killall Dock

and they didn't solve my mouse problem either.

I'm thinking it has to be a software problem. Maybe it'll be fixed in a software update soon, but for now I'm just hoping someone knows a way to reset the part of the computer that causes the unwanted scrolling so I don't have to restart my computer several times in an afternoon.

If you can help, I will be tremendously grateful. This is such a puzzle to me. Happy to answer any questions.