I think that there's some bad definitions in node.twig in node component:
author_attributes is used as a class array
{%
set author_attributes = [
'author',
]|merge(author_utility_classes ?: [])
%}
In line:
https://git.drupalcode.org/project/radix/-/blob/6.0.x/components/node/no...
so is not going to be compatible with the posterior:
<div {{ author_attributes.addClass(author_utility_classes) }}>
in https://git.drupalcode.org/project/radix/-/blob/6.0.x/components/node/no...
replace author_attributes array with new array author_classes to be used as parameter by the author_attributes.addClass method.
Fixed
6.0
Code
Oops, yes that's a mess for sure, thanks a lot for pointing that out and of course for the merge request, merged.
Automatically closed - issue fixed for 2 weeks with no activity.