This is the second Logitech mice I've had that has had this issue. I've been wondering for the longest time why my mouse wheel would sometimes increase the font of the page i'm on for no reason when i sometimes use the scroll wheel to scroll pages AFTER using the switch tab shortcut (CTRL+Page Up). Now I'm happy to find out that I can reproduce it. It seems it involves any pressing of the CTRL key to set things off.
So if you can try this:
1. in Chrome, use "CTRL+Scroll Up" to increase font size
2. on the same page, just "Scroll Up" with the mouse wheel
3. font size should increase again as if you had press "CTRL" also
I tried this outside of Chrome on the desktop and with Internet Explorer and could not reproduce the issue. I'm using the latest version of the software for my G500S mouse and for my Anywhere MX Mouse on my laptop. Happens on both systems, Logitech mice and Chrome browser.
So if you can try this:
1. in Chrome, use "CTRL+Scroll Up" to increase font size
2. on the same page, just "Scroll Up" with the mouse wheel
3. font size should increase again as if you had press "CTRL" also
I tried this outside of Chrome on the desktop and with Internet Explorer and could not reproduce the issue. I'm using the latest version of the software for my G500S mouse and for my Anywhere MX Mouse on my laptop. Happens on both systems, Logitech mice and Chrome browser.