Yeah, just bought Sonar Pro after years of 8.5.3 and X1, none of the feature requests made for DECADES have been addressed, like vari-speed, latching auto-play, latching auto play-then-record-in-to-out, "unsolo all" and "un-arm all" shortcuts, etc...
FWIW, you can work around it by assigning Ctrl+S in track view shortcuts to "solo", then when working- Ctrl+A (select all) then Ctrl+S will un-solo all tracks. It's a workaround, but- no mouse. Same with defining Ctrl+R to arm track, etc.
So many things have been removed that were essential and functional to me after 8.5.3. it's hard to use the new software for me, I bought the newest for support, but will run my studio in 8.5.3 since it has so much more flexibility in configuring, especially in custom defining the GUI. I have NO idea what the Bakers are thinking when they remove so much functionality in customization! Dang. I mean, auto-blacking out the waveform display when adding a volume envelope!??? WTF!