They got back to me and gave some good advice - the first part is only in regards to my issue with MIDI so you can ignore that, but the other stuff might be helpful to you:
From Fractal:
I'd suspect that the MIDI being sent may contain some extraneous data or message that is causing this problem if it is not happening through the controls on the AX8 itself. If you can confirm this is not happening while using the AX8 and its built in switches and controls then this could confirm the issue is from an external source.
If you find it is only when using the external midi control, you could use software like MIDI OX to monitor the midi messages being sent to the AX8 and see if you can track down the unexpected message.
You should also look to see if there is a pattern to it that can be replicated and then when it happens look to see if there is a setting in the preset, like the amp level, that may be unintentionally being changed with a midi message or if maybe it's going to a unexpected scene for that preset that has undesired settings. Also check to see if it's always happening on one preset or when switching between two presets always. Any information regarding the pattern of the problem could help troubleshoot the issue.
Another thing you could try is to reset the device completely to factory condition by reinstalling firmware 10.01, resetting the system parameters and loading the default presets. This can help troubleshoot if this is an issue with the setup of the AX8 for some reason or if its a preset issue. If you find after a reset it is working as expected again, then I would start to add in your custom presets again one at a time and see if they start to introduce the problem again. Make sure you make a back up of your unit using fractal bot before doing a reset as this will erase all settings and presets.
If you'd like to send in your presets and system settings we can also take a look here and see if there is anything we can find that could help you. Any more information you could give us could help us assist you as well. If you have links to the forum posts you're referring to, and any info to the MIDI device or control you're using could also help.
As a note: the AX8 will not be receiving any further updates as we are focused on our current and upcoming products. While we won't be putting out new firmware for the AX8, we will continue to support our customers with technical support and repair services as long as possible.
