Mine will play them to start with but at least half the time I'll get it pause after some adverts and I have to go out and start again for it to carry on playing
even the native app running on roku ss+ shows this, like the itv app too, sometimes you pause and comeback and have to step through adverts, back to where you left off,
as a consequence I'll often momentarily re-start/stop programme, every 20mins or so.
the apps sd image quality usually seems better than freeview though, which i guess is h265 versus mpeg2, plus reasonable bitrate. ...neither of them give 1080.