@TP-Link I investigated this further with pingplotter. The problem was not with TP-link deco M9 but with cloud services running on the machines. MagicX cloud service loaded every 10 second. Turned...

@HelloRabbit My testing have shown the following. 2 windows 10 machines have ping spikes every 10 seconds. 1 ipad 2020 have no spikes 1 iphone 11 have no spikes.