Nice that it works now! My guess was just that it might have gotten corrupted in the engine conversion process, since from 5.2 → 5.3 all existing landscape layer blend nodes got corrupted. If that was the issue, then since it works now it should not break again.
Do you mean layer data? I have the layer data setup and ive tried recreating it a few times.
When I updated from 5.2 to 5.3, then recreating the layer data did not fix it. I had to rename all the layers in my landscape material, and then create new layer data for those newly named layers and then reimport all the layer data that I exported from 5.2 (I wanted to keep using the existing landscape and level).
But since that landscape/material/level works now, it should not break again if that corruption was the issue.