Not only this, but only a couple of days ago I had to buy tickets on two specific flight numbers. Both sectors had availability but not together on the website or mobile site (even though other combinations had availability on the required sectors on the sites!). Luckily I was at an airport with an EK ticket office which was able to create the itinerary for me (they also thought that was extremely strange), but it was quite inconvenient, especially as I was charged in local currency, not originating city currency!

They must fix this soon - did you write in to Customer Affairs to prod them into sending feedback to IT?

As a note about call centres being closed - as a Platinum member, I advise you in calling either the UK call center using the 03 number via Skype or other cheap method (or another 24 hour center), as it is never closed and you will automatically be redirected to the DXB based Platinum line in any case.