Scroll direction inverted using mouse wheel in Firefox (Mac and Linux)

[gav-]

When editing a long table with many rows, and using the mouse wheel to scroll through table, the direction is inverted from normal page scrolling, completely confusing and super frustrating.

Trying to be clear:

• Pushing the mouse wheel away (up) scrolls my web page towards the top of page, but the editable table towards the bottom
• Pulling the mouse wheel towards me (down) scrolls my web page towards the bottom of page, but the editable table towards the top

This is under Linux Mint 20 (Ubuntu 20.04) using Firefox (90.0.2). The problem does not appear using Chrome (90.0.4430.85)