I just want to let everybody know that the Zorin OS 16.3 (Core) ISO works just fine when installing from USB for me. The problems I had with the 16.2- and 16.2r1-installers are not present in 16.3 when installing on my Dell XPS 13 9370 (2018).
This also applies as a solution to this (my earlier) thread:
Job well done everyone involved in developing Zorin 16.3.