Recently purchased templates worlds from the marketplace are able to load into the system and  initially work fine. After any number of save and quit actions, although usually within the first 3, all content from the template disappears. You are left in an empty world with no option but to fall to your death over and over. This has been quite distressing for the kiddos. The two mods this happens most frequently with are listed below. I have attempted to use the windows repair option for Minecraft and reinstalled and as far as I can tell the problem persists. 

It should also be noted that cursed forge or any other external mods have never been installed.

Walt Disney World Magic Kingdom by Everbloom Games (Featured heavily in marketplace adds)

One Block [?] by MelonJP

For Reference here is the system build info 

I7 11700

ASUS ROG Strix B560 A Gaming Wifi MOBO

EVGA 2060 Super (8 GB VRam)

64 GB DDR 4 Ram

Samsung 980 Pro SSD (PCIE 4 NCME Slot)