I've noticed that including the serial library in the squirrel section causes the wireless connections to be dropped when running a nut ... even blinkey. Also, it leaves the USB port in a bad state. The only way to recover is to disable and re-enable the USB port.
An archive of community.esquilo.io as of Saturday January 26, 2019.
Selecting the Serial Library causes communications to be lost when running nuts
It's due to a known issue in 0.3. We're readying 0.3.1 to fix it and a few WiFi reliability issues.