Have you grown Astrantia from seeds? They seem to be hard to germinate from what I've read.

Astrantia seeds germinate in the 40°F range, and usually require a warm treatment first. Plant them now, and they ought to come up next spring.

I find the seeds must be fresh and planted soon after ripening. I've only been able to germinate seeds I've collected myself, none that I bought but maybe others have had a better experience than me.