@Tce The reason your Wifi is also below 100 mbps when connected to the Archer A5 is because the ehternet backhaul connection from your A5 to main router is limited to 100 mbps. You A5's 100 mbps...

@SoilH2o It is not uncommon for any router to need to be restarted following a modem reboot or loss of connectivity. A useful way to mitigate this, if it is a common occurrence, is to setup a reboot...