I had this issue today on https://app.netlify.com/signup/email
I used a suggested password and it wasn't saved anywhere.
MacBook Pro on 13.4.1 (updating now though... I haven't been getting alerts about new versions for a while!)
Orion Version 0.99.126.4.1-beta (WebKit 618.1.2)
edit: I just noticed in Settings -> Passwords there is an option for "Offer to save passwords to Orion's keychain" which was not checked. Is that why this happened? Why would that be an option?