The fit should be comfortable. I can’t tell if mine are on/in unless I reach up and touch it, and that’s the norm. It has to go fully in the ear canal. It could be that the dome is not the right size, and it is easy to try another size.
You mentioned double-domes. These stop up your ear and your own voice sounds loud. Custom molds could have a vent and maybe those will be more comfortable. It takes a couple of months of wearing them 18 hours a day to get used to them.