Converted version 1.12.2 to 1.13

Vanilla Survival world. Never used any mods or cheats in world.

Buried treasure chests are not generating.

I have found 2 treasure maps and located the red X. After digging for a long time looking for the first one, I finally made a copy of my server and checked around in spectator, nothing.

Did the same for the second and nothing again.

I am now worried buried treasure is not generating on my world.

What are my options/solutions? Please help.