Check if you don’t have hungry modules on the same rail, oddly I have 2 digital modules ( Graphic VCO and Waverazor ) on the same rail that were responsive as usual, since I rarely use all of them simultaneously I had to unplug them to recover a responsive Shapeshifter.
Maybe the 2.04 firmware ? the layout on the rail is new so I have no background …
Doubt it’s firmware related but possibly the voltage was dropping too low on the rail for the onboard voltage regular to run at full voltage and that may have caused some performance issues if it resulted in it being underclocked or something. Weird though 
It’s definitely a ( local ) power issue, was always on the same Doepfer LC9 case which is no slouch with more than less ( !! ) the same modules constantly rearranged with the newcomers …
I haven’t run a Modulargrid “simulation” but problem occurred with Graphic VCO - Shapeshifter - TriTone - Waverazor - Geiger Counter on the same rail and the 2 other digital modules weren’t laggy at all ( as a E370 rail above since before the " incident ")
No big deal, solved easily, but weird indeed !
Undervoltage isn’t necessarily going to make all digital modules lag or react in the same way, it’s probably just a peculiarity of the hardware used for the Shapeshifter.