I've also had that problem, but the other way around. Some saved itin disappearing from my computer, but not from the server.

The planners been loading very slowly for the past few days, and at times, doesn't allow me to click the 'book now' button, even though the trip is complete and there are no problems.

It appears that they've added in a premium ecomony option. If a Y+ upgrade is possible on the carrier/sector, there is a check box which will change the booking class.