Hi Martin,
You have 2 options, you can decide whether the arpegiator is part of the preset or not. See "Arp in preset" in the settings.
If it's part of the preset, the arp is saved and load with the preset... So you won't be able to hear you current arpeggiator with the new sounds you browse.
Set it to "no" and the arp you just edited will be kept... so you can browse the other sounds with the arpeggiator and your arp is not erased by the preset you use.
If what you wanted to do is to browse while holding keys and that changing a preset do not stop the arpeggiator... you cannot. I may add that later.