i opened a ticket, this is the answer....it's not a bug...it's just like this
Sad..
Thank you for your email.
The situation you are encountering is due to the fact that the cab changes when you select a different rig. The recorded loop gets played back through the different cab which changes the sound of the loop. To avoid this you can use the lock function to prevent the cab from changing when you switch to a different rig.
The reason for this behaviour lies in the architecture of the Profiler and unfortunately cannot be changed.
Sincerely,Hans-Jörg SchefflerKemper Amps Support Team