Did my direct access test about 12 years ago,
Partway round the test i had to pull over and wait for the examiner to catch up. I could not hear instructions over the radio, chap had a play around, no real difference, we carried on, i passed 🙂
At the start i was told any bike or radio issues to safely pull over and await the tester to catch up, was still crapping myself i would fail for stopping mid test, but they kind of expect it i assume.
Then it was signal issues and battery issues, as the battery pack ran down the radio dropped in performance (no battery charge indicator)so it was quite possible to have a working set but battery failure part way round.
May be urban myth….you might pick up mini cab radio instead 🙂
Sounds like nothing has improved.