S11 Multi-FX Stopped Working

I received my S11 4 days ago. On  day 2, the Serato FX would only play 1 FX at a time.  One the first day, I could use 3 different Serato FX simultaneously.  I've only been able to select one serato FX at a time since then.  I'm not sure what the issue is.  I'm using Macbook pro with catalina.