When I use a basic template
serialNumberGroup.MapGet("{id}",async (....
var link=linkGenerator.GetUriByName(contextAccessor.HttpContext, "GetSerialNumber", new {id});
The value of link would be the correct.
However if I use constrainst in the template
serialNumberGroup.MapGet("{id:required:alpha:length(1,50)}", async (....
var link=linkGenerator.GetUriByName(contextAccessor.HttpContext, "GetSerialNumber", new {id});
The value of link would be the null.
I have looked in the options to see if there were any settings to adjust the behavior.