"Group by day" rarely works

Hi there,
when I try to group the Pulses within a certain timespan (e.g. 1st March to 15th march) by day, my browser freezes for a few seconds and the Website shows some random pulses from 2008.
This has happened before, but I got it working by trying multiple times - like in one out of three tries I recieved the correct results. But today it won’t work at all.
Anyone else experiencing this issue? Any idea how to fix it?

I have the same issue with that, and also in the Applications list when I want to sort by keys, I have to re-select it about 4-5 times until it works, when it doesn’t work the page just refreshes and sorts by application name, like before.