Files not found for some domains with multi context MODX site

Anybody able to help me with a weird issue?

A client has many sites running as contexts on one MODX install.
Like:
https://mkbvitaal.nl/ and
https://nbpwzorgportaal.nl/

Those work fine, however a new site with the same templates, settings and code can’t seem to ‘find’ CSS or other files on the domain…

(if I change the path to CSS manually to sg-portals.nl all works, but I need to use beonzorgportaal.nl of course…)

DNS settings for all domains are the exact same, as are the context settings!
Checked so many times now that I am going crazy.

Anybody know what this could be?

Maybe something has to be changed in the .htaccess file?

For loading a file from file-system (CSS, JS, image) MODX isn’t involved. So it can’t be a MODX issue if the file is not found.

htaccess has nothing strange, use Xrouting to redirect contexts and other work fine…

The CSS file can’t be found from frontend even with a link:
https://beonzorgportaal.nl/assets/components/sg-2021/style.css

But this one (the MODX install root URL) works fine:
https://sg-portals.nl/assets/components/sg-2021/style.css