I get it that there is MAGIC happening that keeps track of what's going on and so when you import a subflow that is different to the resident one: you get a question about what to do.
So you click the button, examine the details and overwrite if it is newer.
But I'm getting those kind of requestors, but it isn't doing that now.
First question: do both machines have the same version of NR?
Your penultimate image makes me think of a subflow definition replacement: the import code contains a very old logic that compares the imported subflow definition with all existing definitions. If a match is found, your imported instance node will be updated with the existing definition instead of the imported one.
Maybe the answer but I'm writing it from head (memory).
Yeah, the images aren't too helpful, and there are quite a few of them.
From memory NR2.x was not good at subflow imports.
V3.x onwards was great by comparison.
The pictures are there only to show what I was seeing rather than me trying to explain it all.
But I hope you can see that with the machine health was being imported: the requestor and options are very different to what happened when I tried the second one.
The last image says that the subflow definition already exists. Do you want to import a copy or replace it? It also asks if you want to import the subflow instance node.
However, I have a doubt about the image above.
I think it's ask to import a copy of the definition and ask to import the subflow instance node.