When I visited viabtc, I always saw it's already in 0 free submission. If it's a visual bug then I don't know the reason behind it but I haven't heard or notice about viabtc having a visual bug on their website.
The visual bug was probably about the 19 free transaction acceleration slots that were displayed for almost an hour and yet when one tried to enter their TX I did, an error "Submissions are beyond limit. Please try later."