Syncing lines in XY4 in VDosplus

["Paul Breeze" dmarc-noreply@xxxxxxxx (Redacted sender "paul.breeze" for DMARC)]

I have a problem with lines in Vdosplus. I normally set 43 lines for
the window. This is set in Config.txt and also in STARTUP.INT. However
if I exit to DOS, then return to XY4, I return to 32 lines. If I exit
to DOS again and return I have 14 lines and if I repeat a third time XY4
disappears and I have a completely blank window (with the same in
Vdosfln XY4 hangs so I expect that is what happens here.) I have no
idea what is going on but it would be nice if exiting to DOS and
returning could be accomplished smoothly with no line number change.
Any ideas?

Paul