bug: Unable to connect to the NanVNA V2_2

[FilipCZE]

Bug Report

NanoVNA-Saver version: 0.7.3.
NanoVNA board V2_2, firmware: build 13 oct 2020 (edy555)
Rpi 3B
New PiOS Installed using Pi Imager

LSUSB:
Bus 001 Device 006: ID 04b4:0008 Cypress Semiconductor Corp. CDC ACM serial port

After the start of the program, there is the log:

NanoVNASaver 0.7.3.post1.dev4+gace8e75.d20250309

Copyright (C) 2019, 2020 Rune B. Broberg
Copyright (C) 2020ff NanoVNA-Saver Authors

This program comes with ABSOLUTELY NO WARRANTY
This program is licensed under the GNU General Public License version 3

See https://github.com/NanoVNA-Saver/nanovna-saver for further details.

2025-05-16 07:23:28,450 - NanoVNASaver.Hardware.Hardware - ERROR - No VNA detected. Hardware responded to CR with:
2025-05-16 07:23:28,925 - NanoVNASaver.Hardware.Hardware - WARNING - Did not recognize NanoVNA type from firmware.

After connecting the to device (which is shown as unknown) the log is as follows:

NanoVNASaver 0.7.3.post1.dev4+gace8e75.d20250309

Copyright (C) 2019, 2020 Rune B. Broberg
Copyright (C) 2020ff NanoVNA-Saver Authors

This program comes with ABSOLUTELY NO WARRANTY
This program is licensed under the GNU General Public License version 3

See https://github.com/NanoVNA-Saver/nanovna-saver for further details.

2025-05-16 07:23:28,450 - NanoVNASaver.Hardware.Hardware - ERROR - No VNA detected. Hardware responded to CR with:
2025-05-16 07:23:28,925 - NanoVNASaver.Hardware.Hardware - WARNING - Did not recognize NanoVNA type from firmware.
2025-05-16 07:28:48,381 - NanoVNASaver.Hardware.Hardware - ERROR - No VNA detected. Hardware responded to CR with:
2025-05-16 07:28:48,840 - NanoVNASaver.Hardware.Hardware - WARNING - Did not recognize NanoVNA type from firmware.
2025-05-16 07:29:06,750 - NanoVNASaver.Controls.SerialControl - ERROR - Unable to connect to VNA: too many retries
Traceback (most recent call last):
File "NanoVNASaver/Controls/SerialControl.py", line 89, in serialButtonClick
File "NanoVNASaver/Controls/SerialControl.py", line 128, in connect_device
File "NanoVNASaver/Hardware/VNA.py", line 165, in read_frequencies
File "NanoVNASaver/Hardware/VNA.py", line 207, in readValues
File "NanoVNASaver/Hardware/VNA.py", line 207, in
File "NanoVNASaver/Hardware/VNA.py", line 105, in exec_command
File "NanoVNASaver/Hardware/Serial.py", line 33, in drain_serial
File "serial/serialposix.py", line 560, in read
serial.serialutil.PortNotOpenError: Attempting to use a port that is not open
2025-05-16 07:29:17,821 - NanoVNASaver.Controls.SerialControl - ERROR - Tried to open /dev/ttyACM0 (Unknown) and failed: Port is already open.

The communication log from NanoVNA-app:
00.036 connect: serial port connecting ..
00.051 connect: serial port connected
00.067 tx: leave USB data mode
00.067 tx: 00 00 00 00 00 00 00 00 20 26 02
00.067 tx: are you a V2 ?
00.067 tx: 0D
00.192 rx: 32 .. ACK OK
00.192 tx: requesting device variant
00.192 tx: 10 F0
00.442 rx: 02 .. DEVICE VARIANT OK
00.442 tx: requesting serial protocol version
00.458 tx: 10 F1
00.692 rx: 01 .. PROTOCOL VERSION OK
00.692 tx: requesting hw-revision and fw-version
00.708 tx: 10 F2 10 F3 10 F4
01.145 rx: 02 ..... HARDWARE REVISION
01.161 rx: 01 02 .. FIRMWARE VERSION
01.176 rx: [connected to a V2]
04.821 disconnect: serial port disconnected
(it seems to work fine)

Version NanoVNASaver 5.5.0 pre is able to connect and run the device succesfully.