I was holding BTC funds in Magnum wallet.
Recently, the Magnum wallet was suspended. I was not informed on time for the suspension, and I could not transfer my funds to another wallet before the suspension.

I have my BTC address, private key, secret 12 word phrase.

In the blockchain explorer after entering the address my funds are visible (unspent).

I have created a new wallet in Blockchain and imported my BTC private key. The message was that there are no funds - 0.

In the blockchain wallet the address generated after importing the private key is not the same as my BTC address.

My address starts with 3
My private key starts with K

Can someone assist with a way I can transfer my BTC funds to another wallet?