Benchmark_tx/_rx with small text files

I have a USRP1 board with Flex900 (side A) and DBS-RX (side B)
daughterboards. I tried using commands:
./benchmark_rx -f 900e6 -R B
./benchmark_tx -f 900e6 -T A --tx-gain 3000
and the window prints normal list of packet numbers with stats.

I then tried to send the small text file of README in the
/examples/digital/ folder, using
./benchmark_tx -f 900e6 -T A --tx-gain 3000 --from_file README
However, I get a lot of errors on the receiving side.

Finally, I tried to send a even smaller text file containing the text
“Hello world!” This time the receiver does not receive anything.

I was wondering what is causing this? Similar problem was observed 3
years ago in this post:

Thanks in advance,