but the mouse wheel has been playing up for a while now, occasionally scrolling down when I’m in fact scrolling up.
Are you able to open it up and clean the parts around the scroll wheel? You'd be surprised how much crap accumulates there!
If you are looking, Logitech now offers replacement parts for some of their mice through ifixit: https://www.ifixit.com/News/75363/genuine-parts-for-logitech-mice-coming-to-ifixit
I've got the MX Anywhere 3 as my general use mouse. It works well, but I do wish it had AA batteries, instead of an internal one. I hadn't considered repairability when I got it, but it's nice to know that I can get replacement parts, and a replacement battery, should I need it.