scp drops connection after sending the scp -t command

I'm using Ubuntu 18.04.4
openssh-server Version: 1:7.6p1-4ubuntu0.3
as the destination host.

Raspian 4.19.97+
openssh-client version 1:7.9p1-10+
on the destination host.

command on the Pi is:
scp -vvv filename paul@destination:filename

The debug shows this:
debug1: Sending command: scp -v -t filename^M
debug2: channel 0: request exec confirm 1^M
debug3: send packet: type 98^M
debug2: channel_input_open_confirmation: channel 0: callback done^M
debug2: channel 0: open confirm rwindow 0 rmax 32768^M
debug2: channel 0: rcvd adjust 2097152^M
debug3: receive packet: type 99^M
debug2: channel_input_status_confirm: type 99 id 0^M
debug2: exec request accepted on channel 0^M
debug3: receive packet: type 96^M
debug2: channel 0: rcvd eof^M
debug2: channel 0: output open -> drain^M
debug2: channel 0: obuf empty^M
debug2: channel 0: chan_shutdown_write (i0 o1 sock -1 wfd 5 efd 6 [write])^M
lost connection

The destination shows that the client dropped the connection.

ssh works fine.

What am I missing?