Op every Bitcoin address has it's own special seed phrase.
This is not true.
Each bitcoin address can be generated by a very big number of different seed phrases.
I have made the necessary correction. The big number which you are referring to is actually the public key which is used to generate the respective addresses in that particular wallet. I mis typed address instead of wallet in that particular statement. Funny how choice of words can be that important in cases like this "LOL".
I think your further explanation of this thread actually counters your own point in the first sentence, every address doesn’t have a specific seed phrase rather a single seed phrase can be used to generate multiple child private keys as you stated which in turn can be used to generated different bitcoin addresses. With a single bitcoin seed phrase you can even have addresses of different formats just by creating new wallets and specifying the derivation path you wish to have it. This is what I think OP is trying to do maybe get a bech32 address from his existing private key or seed phrase which he will just simply change in the options when creating a new wallet with same seed phrase
Thanks for the heads up EL MOHA. I actually miss typed wallet in place of address. Like I was trying to express earlier, a seed phrase is for a single wallet and in the case of the wallet being an HD wallet, there could be multiple addresses having their individual private keys which were generated from the master private key which was in turn generated via the seed phrase.