It is a common characteristic of hashes that different numbers can produce the same initials. For example, as in the case you provided, 1BY8GQbnH7ny3ZbLpmVtBZLZ2Lw7528UfK. This is not surprising.


If you really think it has some  connections with the private key, then can you explain why the Bech32 and SegWit addresses of the same private key don’t have the same initials, while only the legacy address does? Does legacy address  have some magic in it?