Switching my main computer to Linux after finally having enought experience with freecad and being done with a school forcing us to use Autodesk programs
In Germany we call it Hassliebe and it describes perfectly what i have with freecad (stupid import an stl way)
Maybe you can Print something Like this First layer Test (https://www.printables.com/de/model/252059-perfect-first-layer-test) so we can get a closer Look at your First layer
Two questions: how high is the nozzle away from the printbed when you Print the First layer and have you done a Testprint to check the bedlevel
Switching my main computer to Linux after finally having enought experience with freecad and being done with a school forcing us to use Autodesk programs