I am using Wio-E5 mini and unfortunately I cannot check your problem because I have already rewritten the firmware.
The easiest way is to change to Grove-LoRa-E5 without CP2102 implemented and send AT commands from Pico.
Also, if you use Wio-E5 mini, you can rewrite the firmware to run the sketch without Pico.
Please refer to some links below.
“Node using XIAO_nRF52840 and Grove-LoRa-E5 running on AT commands, sleep current 6.4uA”
“Programming LoRa-E5 with Arduino, LoRa-E5 mini Point to Point Comminucation over 10 km”