Soundcore a40 pairing replacement earbud

Hello everyone
I lost my right Soundcore a40 bud and i bought a replacement one.
Now i can’t pair the new bud with the case and the other bud, its partially pairing, the touch comand works, but no sound.
I bought the replacement bud with his original case and with his case is working fine.
The problem occurs when i try to pair it with the other bud and case.
I tried hard reset with the case buton.
No ideas left
Please help
Tnx