I'm looking at the "how to claim" guidance and it seems if you're contacted by the app (as DS1 has been) but not by a contact tracer you're not entitled to claim. It's still compulsory to isolate though, so how does that make any sense? Are they effectively saying that if you really need to isolate you'd get a call? DS will comply but it seems most unreasonable that this help is there but not for everyone who will lose pay though following the instructions.
"If the NHS COVID-19 app notifies you to self-isolate because you have been in close contact with someone who has tested positive for coronavirus, but you have not been contacted by NHS Test and Trace by phone, email, letter or text message, you cannot currently apply for the Test and Trace Support Payment scheme"