Same thing here. Variax JTV69S -> 25' Line6 VDI cable -> hd500x -> l6Link -> L2T. Random effect changes and / or the new patch selection doesn't seem to stick or goes back to the previous one. Never happens when I'm on my own - sometimes happens when rehearsing with keyboard players - almost always happens live. I have no MIDI cable or USB plugged into the unit when this happens. This weekend it messed up in front of 10,000 people - frustrating.
Also, sometimes cuts out like I have a bad cable, but I've checked and replaced the cable a few times already.
...and when my volume pot on the Variax is at minimum it will randomly go to full volume after a minute or so. If I move the volume knob it will start tracking at the right level.
Argh.
P.S. All latest firmware updates Driver: 4.2.7.1, HD500X Flash: 1.32, Variax Flash: 2.10
..................
Latest Update:
I now have a support ticket open. I think it may be a combination of two things - a wrong cable and a bad cable.
1) I used a regular XLR cable for the link from the HD500X -> L2t - my bad - the docs "strongly recommend" an AES (digital) rated cable - changed that but won't know until I play live again.
2) bad connection on the JTV (69S) - works rock solid with a regular ethernet with a proper clip (rj45) - intermittently cuts out with the VDI cable (even a new one). This also explains the unexplained sudden volume on when the volume pot is turned down - the JTV momentarily loses it's connection and the patch resets to the default which has the volume at full.
Hopefully this resolves it.