Both Mycelium android app or bitaddress.org come up with the same public address that is incorrect and does not start with 3.
I am doing this within the scope of Trezor testing. Trezor wallet generated with the same same seed offers Segwit addresses but I feel uncomfortable sending BTC to an address whose keys I am not able to restore with multiple tools.
It is not an incorrect address. Segwit address are actually 3 Bitcoin addresses. The old wallet address. The compressed address. And the the segwit address. You just got the old bitcoin/bitcore address but it is just the same. Send bitcoins in that address and it will be placed in the segwit address even if you check the block explorers. Send money to the segwit equivalent same thing will happen. Send it to the compressed bitcoin address the same thing will happen it will appear in the block explorers as value in your segwit address.
You got me properly confused with this one. I guess I have some reading to do.
It isn't the same if you send to any of these addresses, on a technical level, that is all different. You won't be able to make a segwit transaction from a standard Bitcoin address, that is all you need to know for now. If you want to make a segwit tx in the future, you will need to send coins to the segwit address first (the one that starts with 3). Only when you send coins from a segwit address to a segwit address, that transaction is a segwit transaction and it will be smaller then a standard Bitcoin transaction.