Zooming with the mouse wheel does not seem to work properly for me. For example when I’m at zoom level 300m and scroll one “click” back I end up at 3-5km (this varies) while I expect it to be at 500m, just as if I pressed the “-” button on the top right. The same happens when scrolling forth. I’m not having any issues with my mouse wheel elsewhere, it also works perfectly fine on Google Maps.
Tested browsers: Chrome 88.0.4324.190, Edge 88.0.705.81, Firefox 78.8.0esr Operating system: Windows 10 Home Mouse: Logitech MX Anywhere 2S
Have a look at your mouse settings (windows key + type “mouse settings”).
The default for “Choose how many lines to scroll each time” is at 5.
Values higher than that might influence your zoom level steps.
Finally I found the culprit, it was the setting “smooth scrolling” in the Logitech Options software. After disabling that everything works again as expected.