Nectar Rose

Has anyone grown Nectar rose before. Its suffering badly with BER whereas every other plant under the same watering and feeding regime is fine. Ive had a bit of BER before on longer toms such as orange banana  but this variety  seems quite squat so a bit of a surprise. I 've now added a bit of calcium to see whether that helps or hinders but it's very soon going into the compost bin and the 'dont grow again' pile unless I can fix it.