What machine?
Which OS?
What audio interface?
How did you connect your audio?
Do you use a dedicated ASIO driver?
What sample rate?
What buffer size?
…
Please give us more information:
How to report issues and ask properly for help? - General discussion about Gig Performer - Gig Performer Community
Make screenshots (specifically from the midi ports & audio I/O tab) and maybe from your wiring view.
There are way too many possible causes for your issues, but we won’t know them, if you don’t tell us.