I use Mobile Miner on Samsung Note 2 at 30.xx h/s but a day can only earn 0.0x ETN, anyone know why ? 
Something is wrong. That is NOT normal at all.
Is it the first one?
- Oppo N3 : speed ~ 30h/s - earn ~ 5 ETN/day
- Samsung J7 Pro : speed ~ 30h/s - earn ~ 0.0x ETN/day
- Samsung Note 2 : speed ~ 30h/s - earn ~ 0.0x ETN/day
- Samsung S3 : speed ~ 30h/s - earn ~ 0.0x ETN/day
- Samsung S7 Edge : speed ~ 30h/s - earn ~ 0.0x ETN/day
I do not know what the cause is, only Oppo N3 is working normally.
Are they all using the same account, maybe it's one device per account which would make sense ?
They said they had a way for stopping ppl using multiple phones, so it looks like something tripped that protection.
I know others have been able to use a few phones. Maybe you got the other 4 flagged for trying to use more than one phone.