I got the similar issue. I use USB2TTL( ch340 chip) to flash program to ESP8266. I will download driver manually on win10. I try to find a driver in pamac and got nothing about it. This tells me that Drivers are almost certainly built into your Linux kernel already . Then I look for what are my usb drivers. From this I got the way to see driver for usb.
xx% ls /lib/modules/5.13.19-2-MANJARO/kernel/drivers/usb/serial
aircable.ko.xz iuu_phoenix.ko.xz quatech2.ko.xz
ark3116.ko.xz keyspan.ko.xz safe_serial.ko.xz
belkin_sa.ko.xz keyspan_pda.ko.xz sierra.ko.xz
ch341.ko.xz kl5kusb105.ko.xz spcp8x5.ko.xz
cp210x.ko.xz kobil_sct.ko.xz ssu100.ko.xz
cyberjack.ko.xz mct_u232.ko.xz symbolserial.ko.xz
cypress_m8.ko.xz metro-usb.ko.xz ti_usb_3410_5052.ko.xz
digi_acceleport.ko.xz mos7720.ko.xz upd78f0730.ko.xz
empeg.ko.xz mos7840.ko.xz usb_debug.ko.xz
f81232.ko.xz mxuport.ko.xz usb-serial-simple.ko.xz
f81534.ko.xz navman.ko.xz usb_wwan.ko.xz
ftdi_sio.ko.xz omninet.ko.xz visor.ko.xz
garmin_gps.ko.xz opticon.ko.xz whiteheat.ko.xz
io_edgeport.ko.xz option.ko.xz wishbone-serial.ko.xz
io_ti.ko.xz oti6858.ko.xz xr_serial.ko.xz
ipaq.ko.xz pl2303.ko.xz xsens_mt.ko.xz
ipw.ko.xz qcaux.ko.xz
ir-usb.ko.xz qcserial.ko.xz
It seems that I already have ch341.ko.xz for ch340. But it cannot flash in fact. If I use cp2102 chip to falsh, it is fine.
According to [ Can’t connect serial port - Error: ch341-uart disconnected from ttyUSB0](Can't connect serial port - Error: ch341-uart disconnected from ttyUSB0 - #2 by iracigt), Just remove brltty and things will be fine.