I just returned a pair of era 100s to costco. I bought them in December 2024 and was unable to pair them. They showed up in the app as Optimo1’s. 
yep. The box said Era 100, and the label on the bottom. The build quality seemed inferior to my Ones. Have no idea why they would only show as “Optimo 1” In the app, other than guessing that they were originally built as Optimo and then re-labeled for sale as Era100? 
Was super disappointed, and, glad the return was so easy. And I'm going to stay very happy with Ones. 
Anyone else experienced this?