So an quick update and search for some advice.
After a little bit of digging, its been suggested in some threads to "rouse" the yeast. I've done this by agitating the fermenter a little to see if any noticable change happens. After a few hours, started getting bubbles again, so it looks like something happened. This moring it was still bubbling awa, but has now stopped. Temp has dropped back to 20c, so this may account for that.
I took a sample via the valve and its now around 1012-1015. Quite a drop in 5 days from 1040?
If its still not active tomorrow, whats the safest option? it does smell quite like an IPA, but still very cloudy.
Thanks.