I have had first.last since the beta data and firstlast always comes to me when I test it out. could it be that something changed after the beta? but something

I have had first.last since the beta data and firstlast always comes to me when I test it out. could it be that something changed after the beta? but something also changed much more recently I'm sure of it because it's become a huge problem for me recently! people are using my email as their recovery email which I have no option to 'unsubscribe' from. someone signed up with chime (a US money sending service) which unless your in the US there is absolutely no way to contact them about removing your email. I ended up going through the bug bounty programme as a last resort because I was receiving all their transactions and even had their address! I've had graduation photos, blood test results, shipping confirmations, beautician appointments, wedding planning (I had to email the vicar in the end and let him know I wasn't the bride being rude!) I get emails from a primary school and I'm invested in the receipts from a garden centre every few weeks though, they have quite a few rewards points now, they're working on their lawn at the moment and the other month they bought two jellycats! At first I thought it might be someone whose email was at ymail.com but I'm not sure anymore it seems it's not linked to any one country or person either.