Can't change categories in mysplash app

Expected behavior

I expected to see the available list of categories, so I could change it from the default one which is buildings.

Actual behavior

Tapping on the dropdown didn't work, I didn't see any response from it, even the sort button at the right end does nothing.

How to reproduce

Download mysplash app from fdroid.
Open app and login with unsplash credentials.
Check the side menu for categories. And click it.
On the categories page, click on the dropdown arrow, or the tag besides it.
It wouldn't show dropdown menu for other categories.

• App: mysplash android app, downloaded from fdroid.
• Operating system: Android 5.1 Lollipop tablet.

Recording Of The Bug