I had been suffering with very poor landline internet for years and finally took the plunge in December and bought a TP link AC1200 Archer MR600 and have it running with a EE 4G SIM. The first few months have been great - much better speeds and low latency etc. I live in the sticks and the 4G signal is not great so I've recently hooked up a Poynting XPOL  A0002 directional aerial - I now get 2 bars of signal rather than 1 bar and have seen higher speeds - particularly on upload. However over the last month the we've started to have probelsm with streaming and I also play some games and they are lagging/stuttering and it appears that latency has increased massively. If i do a speed test it usually looks OK but if I run the latency test on testmy.net i get intermittent peaks of 1000 to 1250ms and occasionally more e.g. 3,000 or even 7,000 ms! I tried diconnecting the aerial and goingback to the rabbit ears but there is no difference. Also now in the last week or so the wifi signal is poor - it used to be strong across most of the house, I have a BT extender  which helps it at one end but now on my ipad it drops from 3 bars to 2 bars when I walk out of the room that the router is in and then to 1 bar when I walk into my kitchen - which is not that far way, it also drops out completely and then comes back then drops out. In the bedrooms we now get nothing unless the extender is on but the latency through the extender is even poorer - videos are really poor & games are laggy / keep disconnecting and even web browsing takes time. I've tried re-setting the router but there is no improvement! Is my router failing?