I don't see the module usbserial loading
lsmod
Module Size Used by Not tainted
huawei_cdc_ncm 16384 0
cdc_ncm 28672 1 huawei_cdc_ncm
cdc_ether 16384 1 cdc_ncm
cdc_wdm 20480 1 huawei_cdc_ncm
uas 24576 0
brcmfmac 335872 0
brcmutil 20480 1 brcmfmac
sha256_generic 16384 0
cfg80211 819200 1 brcmfmac
rfkill 32768 2 cfg80211
squashfs 53248 44
i2c_bcm2835 16384 0
raspberrypi_hwmon 16384 0
zram 28672 2
zsmalloc 28672 1 zram