Pokemon that are different species and same OT will always get this result. I don't realise why you have gotten this result just now, but if it were a glitch it's fixed itself so don't worry. Just accept the fact that your Pokemon will take longer to breed.
To get the better of the results (70%) you may want to breed with two different-gendered Eevee with two different games. (i.e., different OT numbers)
Hope I helped. :)