Inexplicable events. GPS: u-blox 1 saving config

Hello, everyone,

my equipment is as follows:
-Cuav V5+ with NEO 2
-TFmini plus
-RFD 868
-Copter 4.03

4 days ago I have a Cuav 3DR Radio against the RFD 858
exchanged.
After that the error appeared
“GPS: u-blox 1 saving config”

I thought it would be good to completely reconfigure everything.

I did that, too. “force bootloader” and 4.03 reinstalled.
For 3 days everything was perfect. Today the error message appears again
“GPS: u-blox 1 saving config” and “rangfinder 1 was not detected”
Without changing anything.
I have added the binary file.
It would be really nice if someone could help me.

Greetings
Thomas
2020-06-24 15-10-18.tlog