No, not sure that my explanation and your understanding quite matched up.
Re your comments on Capture1
Capture1 is AFTER I clicked on the Confirmation fact in FS and transferred it to the RM person. I didn't know it was going to "mess up" until after I had done that and seen what was presented in the UI.There was no Confirmation fact in RM before. Yes, the DEATH and ALT.NAME are different, but I did nothing to try to make them the same and they're not the issue.
The transfer of the FS Confirmation fact did NOT put the new fact in the existing RM Confirmation fact, that is why it is still in Italics. Instead, it created a new Confirmation fact (and Fact Type) and with that created a new line on the RM person display which it placed below the Residence lines.
Because it sees the Residence lines as being the same in RM and in FS it has coloured them both green AND aligned them with each other. But the Confirmation facts are not seen as being the same therefore not green and not aligned with each other. Had the Fact Type been the same and the data different then they would have been aligned but coloured in either yellow or white. But because they're not aligned it means that they are seen as different Fact Types - which is the problem.
The two Confirmation facts contain identical data, yes, because I transferred it from FS to RM. This screen capture is not presenting what it WOULD do, but presenting what it HAS done. The data being identical (and therefore green) is not recognized because the Fact Type is different.
Re your comment on Capture2
No, I did not already have a Confirmation fact on that person. There is only one Confirmation fact for this person now and it was **just** transferred in there from FS. Capture5 shows that the only Confirmation fact on this person is the one that has the undefined sentence type which is the new Fact Type created by the import step.
Capture5.jpg-----------------------------------------------------------------------------------------

Re your comment on Capture3/4
I hope you see now that the second Confirmation fact is new and is incomplete. It was not there before. It is used only by the person to whom I just transferred the fact from FS to RM. There was no merging of the new FS fact's data into the existing RM fact's structure. For some reason, the FS fact is not recognized as being the same Fact Type as the RM fact. It has nothing to do with the data from FS that is presented in the UI about the fact contents, and everything to do with the data from FS that is used to decide if a Fact Type coming in matches one that already exists ... or not.
If you were to accept my hypothesis as being possible, what test could I do that would prove to you that it is or is not happening?
Here's one more that I ran in to if you want another to investigate: MCJV-88Z