Apparently the last submission I made few minutes before the deadline is still in the process of submitting because the submission process didn't finish before the stipulated time. I noticed back then but I just stumbled upon it again, and it's still in the process of submitting.

I believe this can be stopped from the backend as it is an unexpected state, and MAY cause uneccessary behaviours to your system.

Others can also check their last submissions for such issue and report such incidence if it's so, because submissions could usually take up to 25 minutes during the competition.