Lauterbach always steps into timer isr

Lauterbach always steps into timer isr

I am new to the Lauterbach debugger (Trace32) and seem to have made some
unintended changes that complicates my debugging.
In the Lauterbach debugger is it possible to disable tracing and debugging
for parts of the code?
In my case, every time I step from a breakpoint I jump into a timer-isr.
This makes it very hard to single-step the code. Is it possible to disable
timer when a breakpoint is hit?
The same with the Trace.List where I almost only see timer-isr code.
I'm not interested in the timer-isr at all and would like to step and
trace the application code.
If I remember correct I didn't have this problem before and I might have
changed some configuration in Trace32.