I don't know if this is a useful tip - or more of a 'Der, how could you not know that?'. Sorry if it's the latter.
My wife recently signed up to GHA Discovery and - even more recently - got to Titanium with our stays at Oaks Townsville Gateway, Pan Pacific Melbourne and Avani Residences Adelaide.
We thought this would have happened sooner, as we also stayed at the Avani Jazz Corner in Melbourne straight after the PanPac (and loved the room). As the booking accrued D$, we assumed it would count towards status. But we found out after the stay that it didn't.
On some subsequent digging through dummy bookings, I found that the rate we chose had this rider: Exclusive to Minor DISCOVERY members. So not relevant to the broader GHA Discovery program. We'll be checking the rate conditions more closely on from now on, in particular for any GHA hotels that are also part of the Minor group.
Cheers,
Horatio