V13: Missing Backoffice Css File

[LuukPeters (Luuk Peters (Proud Nerds))]

Seems related to:

Missing Backoffice CSS Files for Forms - v13.8.0 and Forms v13.4.1

I am looking for some guidance. My Umbraco backoffice - forms in particular - is missing the generated CSS file …/sb/umbraco-backoffice-css.css.v… It works fine on my local development env. but missing on production env. The prod env. uses the Production Runtime Mode.