BBC high-quality Radio 3 aac-lc stream won't play

I haven't tried to use the Radio 3 high-quality stream for many months, but when I tried this evening, I just got silence. The 128kbs MP3 stream plays fine, on both my Duet and SB Touch, but the aac-lc stream plays on neither.
I run LMS 7.9.1 on a Pi, and use triode's BBC iPlayer plugin v 1.5.3. Can anyone help?