There seems to be a bit problem booking tickets after 8th July on the Portuguese Railway CP.
I emailed them asking when the problem was likely to be fixed. Their answer is below...
We received your communication that deserved our best attention.
For now, it isn't possible to purchase train tickets for the 8th of July
and onwards, since the timetables will be revised.You are able to
purchase or reissue this tickets only after Jun. 18 th.
We appreciate the interest shown. Communications from our customers are
essential to assess the quality of our services and improve them.
CP Comboios de Portugal