The grey blobs that merge together are because that's what disabled mw-ui-checkboxes look like. (@Volker_E ? @Jdlrobson ?) They become un-disabled when you make a selection in the dropdown.

The dropdown not working at all on an iPhone seems more mysterious though.

The mediawiki ui checkbox doesn't seem to have a disabled implementation so this will need to be added.

The dropdown works for me, it's just completely unstyled as Minerva uses a reset css file and never relaxed it for select's when we moved to mediawiki ui. Can be easily fixed by relaxing the select css rules inside MobileFrontend or replacing it with a OOUI widget.

With iPhone6 (9.3.2) on RC page is not possible to make Namespace selection

@Etonkovidova, are you sure about this claim? I don't have iPhone, but when using simulator, dropdown menu opens in separate panel, in both Safari and Chrome. I know that using simulator isn't the same as using real device, but can you recheck? Any kind of indicator (like down arrow) is missing though. Here is how it looks:

Other two points look the same on my simulation, with checkbox displayed grayed out only when disabled, like explained in previous comments.

@Petar.petkovic yes, the most recent UI looks like your screenshot - no overlapping grey squares, so #1 and #2 are invalid now.

#3 is rather a minor issue.