Thanks for replying with your issue, I appreciate it.
I have a designated folder that I have most VSTs installed into and my other midi controllers have not had any issues like the Keylab has. This issue happens when I run a VST in stand alone and within a DAW, so it does not seem it is isolated to Analog Lab as you've mentioned. Also I did a complete reinstall of the software, have the latest firmware update and have factory reset the Keylab.
What it seems to me is that the signal to the particular key (which in my case is the D3), has a signal issue because when I first power on and start playing, that key does not play when all of the others are responding as they should. After some time though (usually after 15 or so minutes), it seemingly starts to respond better as far as playing, but still getting a corrupted signal to where it does not function as it should. Also, playing the key with different velocity does not seem to have and effect.
At times I'll hold that particular key down and release. I then will play other keys and come back and try that key again. Sometimes that seems to wake the signal?
I was instructed by the support team to open up Midi Control Center and send them info as I'm playing the keys to see if they are getting the proper values, which I did after the D3 began to work to where they could see the midi value it sent to MCC.
I'll keep researching and hopefully find more of you that might have had similar issues so we can figure out if this has to do with an internal hardware issue, software issue, etc.