Maps brought in via Load Level Instance that contain Nav Link Proxys configured to use the Smart Link instead of the Simple Link end up creating a link at the center of the world instead of their actual location. For long and detailed version of the repro steps please reference the linked post.
This was reported and tested in 4.21.2 (CL-4753647). This was reproduced in 4.22.1 (CL-6063286)
Results: At the cut in the nav on the floor out in front, there is no green double arrow going across it. However, if you look at the center of the MainLevel's floor, you'll see the green double arrow right there.
Expected: In the center of the floor you spawned in there is also a cut in the nav, but there is no navlink across it.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-74858 in the post.