Unable to use ProgTrack when using Arduino Mega and Ethernet Shield

[DaveFH]

I want to use the DCC++ Base Station with my Ardunio Mega and a Arduino Ethernet Shield.

Compiling works, Main Track works...
But programming decoders on prog track didn't work.
It seems, that the Base Station did not recognize any anwsers from the decoder.
On Pulse View DCC Communication doesn't show any abnormalities.

Update 25.10.2021 / 20:15:
It does not work even with the Mega when I remove the Ethernet Shield

Update 25.10.2021 /20:55:
Tried some a few other PINs insteadt of pin 2, without any result...
Tried the original DCC++ base station with the same settings an the same boards, it works...