AccessTokenTrait::__toString gives different result each call

[KngGroup]

Due to new DateTimeImmutable() is used inside convertToJWT method, it gives different result each call.
Is it possible to add $issuedAt property to make this method pure?
Many thanks

[Sephster]

Thanks for pointing this out. I'd never really thought that the to string method might be called more than once but makes total sense.

I will get a fix out for this soon. Working on getting a release candidate out for v9 just now so will see if I can bundle it with that. Thank you

[Sephster]

Fixed by #1480