Allow Save after choice in Participant "About You" GUI

in the participant GUI in the About You questions, for some reason one is not allowed to click save after having made a selection, in multiple selections possible questions until one clicks somewhere outside the menu showing the selections.

As below, even though I have selected the only option I want to make, the save button is greyed out. It confuses me, so I guess it confuses others.

Also incidentally, the above question should I think be which brandS of tea in the plural but I am not 100% sure.

Or is it deliberate to prevent participants from making one selection and pressing save, forcing them to think about it and look for other options that are appropriate? If so I think that there it would be better to encourage participants to add other options by having a please select all that are appropriate or are no other options appropriate or something directly connected with the behaviour that Prolific wants rather than just confuse participants into clicking around.