I just installed Vw2023 SP2, and on a file that looked correct in SP1 -- I am now seeing lines between coplanar objects in all of my SLVP.   These wall objects are perfectly coplanar, and these lines did not show up in SP1. No other changes to the file or SLVP other than opening it up in SP2 and updating the out-of-date viewport.  One step forward... two steps back...