Wall joins change after flipping plan

[Mitchell (the other one)]

With some time on my hands I'm moving from VW2019 to VW2020.  It has been a mixed experience.  The first image attached is a floor plan I'm working on.  The second image is the same floor plan flipped horizontally.  And now all the horizontal walls have broken their joins and extended the depth of the wall they were attached to,.  Both plans are in the same file, I duplicated the layer so I would have an original and a flipped layer.  I drew a marquee around the plan, then Modify > Rotate > Flip Horizontal.  And then the result you see in the second image.  Any explanations / guidance would be appreciated.  It only takes a few minutes to repair the walls  . . . . . but I shouldn't have too.  And now I'm calling it a day and going for a beer.

Upper suite original.pdf Upper suite flipped.pdf

Edited September 7, 2020 by Mitchell (the other one)
added plans as jpeg for easier viewing

[P Retondo]

It's probably easier and better practice to flip the plan by flipping the sheet layer viewport, assuming the mirrored unit is identical.  You can use flipped viewports to assemble a 3d model if that's needed.

[Boh]

Also instead of flipping 180 maybe mirroring would give better results? Mirror tool lives in the basic tool palette.

[Mitchell (the other one)]

Ahhh, hadn't thought of the mirror tool.  But alas, no joy . . . . . . . . I also tried grouping the floor plan before mirroring, same issue with the wall joins coming apart.

[bcd]

I second the Flipped Viewport instead, assuming as said that the flips are identical.