My PM6 Plus (last Version on a Windows 11 machine) need about 25 up to 40 Seconds startup time.
I think it has to do with the number of catalogs and pictures and it is normal.
Unfortunately, PM6 plus does not show a startup screen. However, this would be helpful with such a long loading time.
Sometimes I am impatient or don't know if I have already started PM6 and start it again, only to get an error message (no second instance of PM6 allowed).
Maybe a progress bar when loading big catalogs would be helpful.