Check-in problem: calendar not allowing me to select DOB

I'm busy checking in a group of people but cannot seem to check in 3 of the party. I cannot check them in online because the calendar isn't allowing me to select their correct dates of birth.
Their birthdays fall in the middle of the holiday, perhaps this is the issue? So, they are "children" for the outbound flight and "adult" for the return. Perhaps this is the issue, as I was able to check in other younger children without any problems.

Can somebody please advise what I should do here? I've scoured this forum and Ryanair's FAQs and cannot find any mention of this particular problem.

Thanks!
Confused Flyer.  

I had the same problem this morning.
Despite selecting MAY from the Calendar it displayed /04/
If I select APRIL it was correct /04/
If I selected JUNE is was correct /06/
Just seemed to be an issue with MAY
I used the online chat service and they entered my Passport details for me, so there is clearly a problem with the Calendar.
Bit worrying in that if I hadn't noticed my Passport details would have been wrong and incurred a charge at the gate or not allowed to board??
I did a screen dump of the problem just in case!!