My Exemplar Guardians keep disappearing

A few days ago i purchased a Crimson Exemplar guardian for 900 gold and used it for a few matches. Turned the game off and came back later and it was gone from my guardian inventory and my gold was lost.

Yesterday, i purchased a common Exemplar guardian and again used it right after with no issues. I log on today and it’s gone as well. I’ve lost two guardians and a lot of gold. Everything else seemingly works okay. Can anybody help me resolve this problem? I’m playing on an Xbox series X.