Cannot seem to update apps or download from iTunes on my iPad Air anymore. If I hit Update on an app, the circle appears, then just goes back to update status. Same applies if I want to download something: the circle appears and then goes back without doing anything.
According to Gotta Be Mobile, this problem comes up from time to time across various versions of iOS. I'm experiencing it now on iOS 9.3.3.
In my experience, I went to update several apps, only a few actually downloaded. Other ones would show a progress indicator for one second and return to sayIng Update. It also seemed like I couldn't search for apps or see descriptions of apps that showed up on the Featured page after going to those apps pages.
The Gotta Be Mobile site listed three suggestions. The first, which is rebooting the iPhone, seemed to fix the problem, but only temporarily.
The second, try tapping the update button a lot of times and it might eventually work, actually worked for me, and once it started downloading an app, the App Store in general appeared to begin working better for me.
The third solution they suggest is just to wait it out, that the problem tends to go away with time or future updates.
And of course, you could use iTunes to install updates if you need to.
For me, for the time being, I just have a bunch of Update buttons that sometimes work when I tap it, sometimes doesn't, and I hope the problem goes away soon.