Maybe look at the soap you are using
How I read it; it is a preparation deep cleaning soap designed to clean the car to get ready for CC. Yes it says Maintenance but will leave nothing behind; like you said "there was no coating on the car at all"
Info taken from their website:
https://www.feynlab.com/product/pure-wash/
"FEYNLAB® PURE WASH is an impressive deep cleaning car wash soap! IDEAL for the Preparation & Maintenance of Ceramic Coatings because NOTHING is left behind on the surface."
"Ideal Preparation Wash for all Vehicle Surfaces Prior to Ceramic Coating Application"