It's because RB initially opens up in basic DAW mode like a Sonar or Reaper. DAW mode means it's not going to do any generating of anything either midi or RT's. It's just acting as a regular DAW. It's when you click on "generate" for the first time it then goes into full generate mode and it can take 10 seconds or so and it appears it's locked up but it's only configuring itself. This was a wishlist item a couple versions back. There's lots of people who don't care about using RB to generate new tracks, they use Biab for that and then D&D the track into RB because RB is way slower at generation than Biab is. The complaint was "why do I have to wait for all this before RB first opens when I'm only going to do some audio editing and not planning on generating anything"?

Bob

Biab/RB latest build, Win 11 Pro, Ryzen 5 5600 G, 512 Gig SSD, 16 Gigs Ram, Steinberg UR22 MkII, Roland Sonic Cell, Kurzweil PC3, Hammond SK1, Korg PA3XPro, Garritan JABB, Hypercanvas, Sampletank 3, more.