1. Why it is not visible on blockchain.info despite a BTC address? / how it does work really?
Many services and block explorers don't support Native Segwit addresses (bech32 addresses starting with bc1). They will show up as invalid when using those explorers. Simple use one that supports it (e.g blockchair) and they will show up.
Thanks for this suggestion dear. Just I have tried and I found the transaction details without any error.
2. What are the wallets BTC address are SegWit eligible BTC Address?
Segwit addresses may start with a 3 or bc1. But, not all 3 addresses are Segwit.
Yea I knew that Segwit address starts also with 3 . But I did not mention it in the OP because all 3 are not Segwit. Anyway, can you kindly tell me, sir! which wallet can I use for Segwit eligible BTC address?