In addition to iperf, I tested it through a Virtual Desktop - in the
game HL Alyx. To check, I select the H.264 codec, because allows you to
check bandwidth up to 500 Mbit/s. Stable operation is only possible at a
bitrate of up to 300 Mbit/s, further...
I confirm that the problem is not solved. The channel speed constant
1200 Mbit/c (at 5 GHz), while any real speed tests (iperf, games,
skybox) still show a "square form" with an interval of 2 seconds - from
700 Mbit/s to approximately 350 Mbit/s.