Several times now, the Code 25 has locked up on me when trying to use it from the Gateway App on my iPad. Symptoms are that the display will freeze up (text no longer scrolls) and the different buttons (including gain, tone knobs, etc) will become completely unresponsive. Controlling it from the iPad will no longer work either. The only thing I can do at that point is switch the amp off & on again.
Additionally, trying to connect the app to the amp is really hit and miss (yes, it's paired successfully): sometimes it refuses to work, sometimes it will freeze the amp and sometimes it will work, but switching from ipad to amp presets will not.
I worked out the root cause of this problem: this only happens when the amp is also connected to my iMac via USB and the iMac goes to sleep. At that point, none of the buttons/dials on the amp still work. Once the iMac wakes up again, the amp also becomes responsive again.
Can we ask what version iPad you are using with the app?