Salim,
just a suggestion for FT8 settings.
The AGC must be switched off so that the received signal is not amplified, then your answer is correct.
It can also be seen in the waterfall that you are overamplifying the incoming signal.
The rf gain must be taken back so that the background in the waterfall is blue or dark blue... it can be black in some places.
Feel free to restart if you feel something is wrong, but it was fine before.
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Gyula HA3HZ
HA3HZ