Interesting: my piano setup at home (Kronos→USB→Pianoteq→JACK→Firewire→Focusrite) seems to have a latency spike when I haven't been using it for a few hours. The first key I press has notable latency (~150ms?), after that it's normal. I wonder what in the stack causes that.
There is no analog in the entire chain (other than after the Focusrite, which would be the speakers). Thing is the streams etc area always running, there's no "sleep" involved. USB shenanigans on the MIDI side, the Kronos, or e.g. Pianoteq getting swapped out perhaps?
