404 error on giveaway URLs trimmed after the code

Steps to reproduce:

Pick any giveaway, eg: www.steamgifts.com/giveaway/AAAAA/ABCDE, where AAAAA is the code and ABCDE is the name of the game
Trim the URL after the code to get www.steamgifts.com/giveaway/AAAAA

404 error is shown while trimmed URLs like this used to work before. It does work if the forward slash or the slash + any text is appended after the code but not without.