iOS full screen app opening new windows

Does anyone know if it is expected that after adding a rails web app using turbo to your home screen and using the <meta name="apple-mobile-web-app-capable" content="yes"> if its expected that links open in a popup/overlay safari window?

Admittedly its been quite a while since ive done this, but SPAs and sites using tools like pjax used to make this work.

Wondering if I am misunderstanding, if this is an ios bug, a turbo bug, or just not intended behavior anymore