"Show only people" does not work

For all .pet projects in file "O:\experiments\2020.10.14_Bochum_Uni_Social\export\Videos_fuer_Trajektorien" the selection of the "only one person" option does not work.

(It does, though, work for old projects opened with the same PeTrack version)

Exemplarily I describe the issue for file "2020.10.14_Bochum_Uni_Social_Lauf6.pet"

before ("show all"):

after (only change: "show only people: 7"):