OK, lmddgtfy 
https://wp.puri.sm/posts/librem-5-june-software-update/
Work has continued to extend wys to instantiate PulseAudio’s loopback module—which ties the modem’s and codec’s ALSA devices together when a call is activated, and de-instantiates the module when the call is terminated. Since this causes conflicts with hægtesse, a scheme was devised to keep both hægtesse and wys from running at the same time.