TNT frequently counter-program their original fare during the summer, to counter-program the standard fall/spring schedule of most networks. Many basic cablers do in the states. (Mad Men has traditionally run during the summer for AMC, though they show other series of theirs at different times of the year.) Point is, it's not uncommon though the wait is frustrating given that we're not yet at the start of the current fall season. Sigh.
Anyway, the bonus is that if Jamie's role is only recurring, he may yet have time to do other gigs. That air sooner. ;)