This is going to be worthless without pics, but I'll give it a shot. I can send pics of what this looks like, but don't have anywhere to upload them.

Usually, as we all do, I use the thread jump button on the right side of a thread, to either jump to the last post of the thread or the last post I viewed.

OK, so I first noticed this maybe a week ago. Every once in a while, I notice a set of jump buttons is dark blue. When I touch it, it opens up a phone options menu (same as what appears if you click a phone number in iOS). Usually after deselecting the menu and re-touching the button a few times, it lets me click through. It's not too terribly bothersome, but I'm sure it's not intentional.

Equipment: iPad Air 2 that's linked to my iPhone for voice calls when on Wi-Fi. ETA: using Chrome.