Rank up gem bug

Myles247

Just got a 6 star mutant rank up gem 4-5 from completing all carina challenges V3 and cant use it on any of the eligible champs. What am I doing wrong here??

ahmynuts

Do you have a rank 4 mutant and enough gold?

Myles247

100% 3 rank 4 mutant champs, over 10mil in gold.

MrSakuragi

That doesn’t sound right. Post a picture of the champ rank up screen

Myles247

Deleted the app multiple times and was finally able to use the gem.