[Edi]

Domes are like very stupid guard dogs. They are told "Do not let ANY spells in!" and they take it very literally. It was that way already in Dom2. I only made that mistake once when one of my air mages bounced off a dome and I've known better ever since.

The reason why returning works is that it is not targeted at a province, it is targeted at the individual and the effect whisks that individual to the province that has the national capital flag for that nation set.