I would try to gather data to confirm/refute your observations. On you machine tcpdump -i <wifi0> -w WIFI.tcpdump& do some tests, including ping something across wifi but local (on wired) wget something largish (16 MB?) from the other local box wget something from the system under test from the local box then kill the tcpdump and install graphics/xplot-devel read all the READMEs tcpdump -r WIFI.tcpdump -S -tt | tcpdump2xplot and look at the traces of tcp. tcp is very sensitive to loss and I find these very illuminating, but it takes a lot of tcp understanding to get the most out of it.
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