How can I find out what is causing Excel to scroll 15 rows at a time instead of 3?

I'm running Excel, Version 2012 (Build 13530.20376 Click-to-Run) on Windows 10 Enterprise, Version 1909, OS build 18363.1854, on a Dell laptop.

Normally, when I'm looking at an Excel spreadsheet, I can use the two-finger scrolling gesture on the touchpad to scroll up and down 3 rows at a time. That's the behavior that I want.

Sometimes, however, the two-finger scrolling gesture scrolls 15 rows at a time instead of 3. I'm able to change it back to 3 by going into the Settings app, going to Devices / Mouse, and changing the "Choose how many lines to scroll each time" setting from 3 to something else and then back to 3. (That setting is never set to 15.)

This tends to happen about once a day. I haven't been able to tell if it happens at a particular time of day, or when I take a particular action, or what.

What could cause that to happen? Are there any settings I can look at, commands I can run, or anything of that sort in order to try to start to get an idea of why this is happening?

Scrolling in Excel is different to scrolling in say... Word, or a webpage.

Excel will still scroll 3 rows, but if a row is extremely large, the scrolling will be a lot more, which may seem like 15 rows of scrolling.

Basically, the height of a row will affect how much excel will scroll when you scroll the scroll wheel.

To see this in action even better, press the Scroll Lock key on your keyboard and now press the arrows up and down. This will scroll rows by 1. You will see that when there are large rows, the scrolling will also scroll more on the screen. This is similar to pressing the up and down buttons on a scrollbar itself. Note using the scroll bar itself works differently. It will seem to scroll less until you release the button, then it snaps to the right height.