Using the DM, in the discovery_complete callback, after finding two CCC handles from 2 custom UUID's, I can subscribe to only one of the two, the other fails with EALREADY.
I've tried delaying the second subscription for several seconds after discovery completes and it still fails.
Even if I save both discovery contexts (bt_conn connection and bt_gatt_dm_attr pointers), and don't subscribe until multiple seconds later, I can only subscribe to a single one.
It doesn't matter which CCC handle I do first, either will subscribe fine, but the second always fails!
I have only a single peripheral sensor connected. Eventually there will be several....
From nRF Connect App, I can subscribe to both and get the notifications.
Also, the first handle will begin its notifications prior to the second attempt, but those notifications stop when the second subscription fails.
(nRF52840 and nRF Connect SDK v2.0.0)