Tracks - Challange NOT marked as completed?

[gowzef]

I’ve inputted and submitted the flag for the “Lame” challenge within the “Beginner Track” and yet the progress marker (refer to the screenshot – marked in red) is NOT set as completed.

Am I missing something? Why wasn’t this challenge marked as completed?

[gowzef]

Additionally if I try to reinput the flag then the following error message is displayed: “Lame root is already owned”.

So regarding the original question: is this a glitch or a feature?