Too many players in Play mode with IVP

Hi,

I observed a strange behaviour:

This my Setup:

When I enable IVP in Play Mode, I get two extra lanes (copies) at the bottom:

When I save and reopen the score, everything is back to normal:

The behaviour is the same for me in a blank new project.
(I’m on Win 11 latest Dorico)

Solved in Dorico 5.1.70. Thank you!