Not really enough data to give you an intelligent reply.
 

What Mac?

What OS is it running?

Which version of the Sonos app are you running on the Mac?

What router do you have, make and model?

What speakers are connected to the BOOST’s signal?

Have you tried, at least temporarily, wiring a speaker to your router, and unplugging the BOOST to see if that might be the source of the issue?

Have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it?

Macbook Pro 2015

Big Sur

Sonos Controller for Mac 15.10

Netgear Orbi RBR850

4 Play 1’s 1 player and 1 sub (All older models)

I have not tried to replace the Boost with another speaker - not sure how this would affect my computers access to the files on its own hard drive?

Have not submitted anything besides this post.  

This has been occurring for the past moth or so. Ive had the system now for years with few issues. The system has been running form the same computer all this time also.  

Thank you

Sonos controller 15.10 is S2. 

The test is intended to see if the issue is with the BOOST, and not the Mac per se. if the BOOST is failing, it would impede the ability of the speakers to reach the music on the Mac. 

The diagnostic, and the call to Sonos support gives them the ability to see error codes, and other hard data about your system to see exactly what is failing, rather than someone here in the forums having to mentally reconstruct the system, and start guessing at reasons why it is failing, of which their could be many.