Hiding time signature corrupts score
The enclosed score has a few hidden elements, so please switch on "Show Invisible".
Select the 5/4 time signature at the end of the end of the second system. Set it to invisible in both treble and bass.
Save the score. Exit. Open the score. Da da: The hidden time signature reappeared, being preceded by a hidden one.
The score is now corrupt. If you delete one of the two at the end of the second system, the third system is cut to 4/4 although it's still marked 5/4.
I didn't find any way to fix that other than delete bars and recreate them. Very annoying.