There are two major things that affect BVN verification.
1) Insufficient Naira Balance: BVN verification costs #10 (Ten Naira). If you don’t have that in your Naira Wallet, You won’t be able to complete the verification process.
So before you proceed to verify your BVN make sure that you have up to 10 Naira in your Naira wallet.
If all you have is Crypto, then you would need to make a cash transfer to your Naira wallet to complete the verification process.
2) Incorrect BVN details: your BVN details(name, number etc) needs to be accurate if not the verification won’t go through.
If you are unsure of your BVN details, then go to your bank and request a ZF1 form, this form would contain your accurate BVN details.
If the issue persists after you have made provision for these two things, then reach out to support with proof that you have gotten the ZF1 form and the cause of the problem will be investigated.