It may be one of the things you are working on for 2.5.1 but I wanted to report it any way just in case. I have an odd problem with one of my Snap Builder maps and doors. When I generate the map using a seed it generates it the way I would expect it to, with walls were intended and doors where intended. If I save that map and load back in it changes and I now have walls where it should be open and vice versa in some spots. I can send you a copy of the theme and map if it helps, though will need an address to send them to. But I did notice you mentioned some door issues already on the new snap builder, so you may already be aware of this.
You can see what is happening in the screenshot . The top screenshot is what I see if I destroy and rebuild a dungeon using that seed (and similar results with any other seed). However once I save the map and then reload it, the doors and walls get reversed as seen in the second shot.