Since the upgrades when I open ukc I don't see any white icons in the top bar or any category icons left of topic titles. These appear on refreshing the page.
This is kind of what I have using waterfox on a desktop. I've narrowed it down to something thinking it's a tracker or analytics engine, but don't know what's flagging it or why. Edit: starting to suspect fontawesome.com but could be a red herring. Edit again: it was the fontawesome 'tracker' causing the issue for me
Like Paul I'm finding the problem is browser dependent. Are you using the Samsung browser by any chance? When I use my Samsung browser the forum topic icons are looking very strange, but with Chrome on the same android phone they look fine.
I've updated the JavaScript that makes the menu on the right on small screens but it's still playing up a little. It seems to switch the tabs correctly when the page loads but after you've clicked on all the tabs once, you can't click on Bouldering or Winter again. I'll have another look next week.