It had been seen on some kites, if all of them or just some single ones, I dont know.
I recall the LF Elite, a brand new 12 m2 in 20916/17, with a heavier (but not heavy as such) rider, it front collapsed very often - witnessed it myself, really scary to watch.
A really experienced rider, and not overpowered.
A 10 kg lighter rider on the very same kite did only experience this rarely, but it was still there.
Dont know what causes it though
Peter