Have you contacted them for a comment ?
For the sake of trouble shooting it would be quite good to know what iPad and IOS version are being used?
The AudioDamage plug-ins are built using Roli's Juce SDK and as such Audio Damage doesn't have 100% control over the plug-ins behaviour on iOS since it relies on a 3rd party framework which is far from 'bug free'...
Worth noting is also that the Audio Damage plug-ins are quite CPU hungry to boot.
I would be hesitant to blame this on JUCE unless we have some other JUCE plugins for baseline comparisons, I know Jules and this is not the sort of thing he wants his framework known for.
AD have always been dismissive and i did try to politely warn people about them when they started to port to IOS, I would love to buy Filterstation but i simply dont trust them.
This is also why i want the plugin lists here at the forum with issues listed, if you just read the AB forum you would be forgiven for thinking that AD are the best developers on IOS, which they are very far from.
I have given Audio Damage its own section in the bugs list now, lots of issues