Treasure maps break when upgrading to snapshot

I'm playing on a friend's server who upgraded the world from 1.15.2 to 20w13b. Yesterday, he upgraded to 20w14a. When I wanted to use the Buried Treasure Maps I collected before the upgrade, I noticed that all my maps are blank. As you can see in the attached picture. 

I haven't tested it yet if it's the case with newly found maps has the same issue.