So the engineer came and changed the splitter and the cable. Power levels are now:
Downstream varies between 5 and 6
Upstream is 42-44.
I also changed the frequency settings as the guy on the phone two nights ago changed them to awful settings. I set 2.4GHz to 300Mbps and 5GHz to 1.3Gbps and I seem to be back to getting over 150Mbps on WiFi.

---------- Post added 12-01-2016 at 00:34 ---------- Previous post was 11-01-2016 at 22:56 ----------
Speed test at 00:34 on WiFi.