BR: Reason no sound

[Stuttaton]

While Reason rack exstensions generally work well in Waveform, there is one annoyance:
When you start an existing edit, there is no sound from the tracks with Reason (Europa or Thor synths). But it you open the interface, that track starts to play. So you have to open and close the interface for every track, for everything to play.
However, if you quit Waveform and start it again, then suddenly all Reason tracks play, like they should. This happens every time when I start to work on a new day.
Waveform 10.4.2
Windows 10