Maybe it's better to start again, I didn't answer some questions. the motorbike remained stationary for 1 year, when I tried to start it the problem began.
I tried powering the dongle via an external power supply, but the problem remains. When in doubt I replaced the dongle with a new one. the problem remains. perhaps the atmega328 has been unprogrammed or ruined?
the log is the last with the new dongle, externally powered 5 volts

You need to connect a ground also, not just RX/TX.
The baud rate should be 57K.