[ 7.526943] cdc_acm 1-1.1:1.0: ttyACM0: USB ACM device
[ 7.559907] usbcore: registered new interface driver cdc_acm
[ 7.559944] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters
Likely the modemanager is spoiling your fun. See Other Single Board Computers (SBC) apart from Raspberry Pis