Ok, now this is odd.
It’s gone back to 0.00 and 0, so I checked the session cookie again and Chrome now says it was created Monday, June 4, 2018 at 4:45:54 PM
DB says modified 1538557528 and expires 1538558968
Opening the off-canvas cart and refreshing puts the total and quantity back and Chrome now says it was created Wednesday, October 3, 2018 at 11:14:00 AM and the DB says modified 1538558041 and expires 1538559481 - the session id is the same.
All pages are being served on the same URL but clearly something is going wrong with the cookies. I’ll clear them all for the site.
The odd thing is I’ve had this on 2 computers and 3 browsers (Chrome on both, Safari on one).
Hopefully this will fix it. But I’d be interested to know how it could be doing this?