Lots of people have this issue, I'm running Mac OS X 10.11 Public Beta version 5 and my mac doesn't find my Ant+ Stick.
Yes this is annoying but I understand that I'm running beta software and this sort of thing happens but what is also annoying is the childish way this forum is treating those with the problem.
All forums reporting this issue are closed with the same response "we don't support Beta software".
Why can't you a bit more open about it, if its Apple's fault say so and point users to the place they can report the issue to them.
If you are working on a fix that may not be ready for months say so.
The other reason for beta testing is to enable bugs and incompatibilities to be found before software hits the mainstream.
We are trying to help you, the full release of El Capitan is just round the corner you need to be ready.