Gap in Tx/Rx of Bandwith test

Why I get gap of Tx signal when testing bandwith (in both directions).
After some time Tx start transmitting, and then again…

I don’t need to get higher speed (10/10 Mbps is enough for me) but I would like to have it more stable.

What can I do to improve my stability?

TIA
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Are you testing over a wireless link? if so that may be why, wireless is not full duplex so in order to transmit it must slow stop receiving and vice versa.

Perhaps because you’re maxing out the throughput it can’t send data back about the rate?

Don’t know… On some other device it send normally with some fluctuations, but never like this…