FFB loss

Last night and today i've had weird ffb issues, both times i was catching a slide, the ffb has been lost but letting go the wheel and it goes full lock in one direction.
Iv'e had clipping issues but the ffb usually comes straight back when the wheel is relaxed, had the wheel and base for around 3 years and i haven't came across this issue before.
The base is the 8nm csl dd, i dont think it is the usual issue where the stem comes loose as i replaced the clamp with a 2 bolt one and it doesn't appear to have moved since.
All driver's etc are up to date.
Any ideas?