Protobelt -> Zz'rot Portal Bug

So I was playing a kennen game today and did the standard setup of doran's blade with a potion and continue my build towards a zhonya's starting with the armor into a needlessly large. My teammate said "everybody get zz'rot" and I guess they decided trolling would be fun so I joined in. I started with the chain vest, then bought the negatron cloak. After I got a bit of gold, I sold my doran's blade to get the last bit of gold I needed and bought the zz'rot portal.

After purchasing the zz'rot portal, I left the base and found out that my protobelt had disappeared.

This is a game breaking glitch, considering I walked off the base without knowing and found myself 2400~g or so in hole with nothing to show for it. We went on to lose the game (whether because of build choice or lack of power, I'll never know).

Please investigate this bug. I'll update if I can make it replicate.