Just to clarify. My keylab essential was connected to my computer via usb and then I used Ableton 10 Suite as a midi router to my hardware, and I also used Ableton in order to control vst synths as well.
Then there is a lot more variables. This issue does'nt have to be about your controller then, even if it can be.
If i was you, then i would connect your controller to your hardware synth, if you have the possibility I assume Arturia would like you to try that.
If you have the issue doing this, then it look like it's about your controller. Otherwise it can be about many other things including your workflow, computer, soundcard, Ableton and plug-ins, that is'nt a controller issue.
You can also try to play Analog Lab in standalone mode, and not touching your computer mouse or anything else while playing. Does you have the issue doing this?
And you can do the same in a Ableton song using only one track. Does you have your issue doing this?
When you have your issue, then does you touch anything else including your computer mouse? Or do you overload a CPU core or have other latency issues or whatever?
It's impossible to find out what's causing the issue unless it's a know issue, without trying to isolate when the issue occour, and what you do when it occour.
Even how you play can have an impact.