Just that really! Mine tend to flower late May/early June and look amazing. Then the past two years we've had a party for my daughters birthday mid June and the buggers don't have a single flower in sight. They look like big green bushes. Then they flower again in mid July, and maybe once more in late August/early September. They all conspire together to flower at the same time and go bald at the same time, so the flower bed looks amazing or very boring depending on what they're doing.
We have a rose garden locally and their roses bloom continuously all Summer. I keep on top of deadheading, cutting back to five leaves when I remember, and I cut them back over winter. They're all healthy - a bit of black spot much nothing bad, and I water them a bit if it's really hot and dry. I have a Queen of Sweden, Gertrude Jekyll, Glamis Castle and then a couple more David Austin ones too. Does anyone have any lucky with this? Am I doing something wrong? Or is it pretty normal?