British Columbia: Calamagrostis x acutiflora 'Karl Foerster' falling over after rain

I planted Calamagrostis x acutiflora 'Karl Foerster' in my garden two falls ago. It grew beautifully but last summer, after a rain (nothing too heavy), it flattened. I did some reading and found that fertilizing can cause the stems to weaken. I had fertilized (though only with fish fertilizer as I like to keep things as organic as possible), so this year I did not fertilize. I did put a bit of compost around it in the spring. Today, after what can only be described as a very light rain, it is flattened again! I am mystified. I chose it for it's reputation for upright, sturdiness. Any ideas or suggestions would be most appreciated.

 

Photos? We should try to confirm identity.

 

Here are some photos of it - close up of the grass and propped back up with a broom.

 

Well, it sure looks like it to me.

These photos were taken when it was shaded -- is this area generally sunny, though?

 

Excellent question. I thought it was getting a lot of afternoon sun but after checking with my expert (husband), he said the window is actually quite narrow, due to the hedge. That could be it - could be time for a move....