GDB connect to a running target without halting cores.

For debugging an application I need to connect to a running target without halting cores.
If I use only pyOCD in a python script I can set the option connect_mode to attach and I see no issue.
If I use gdb as explained here:
https://pyocd.io/docs/gdb_setup.html
I always need to reset the target, even if I select the connection mode to attach in pyOCD.
Do you have any advice?
