Speed Feed feeding to much line

G'day everyone. A little help will be much appreciated.

I've got a Shindaiwa Speed Feed. I bloody love it, and have been using for over a year with no worries until today.

As the title says, it keeps spitting out line as if its not holding onto the spool strong enough. At full revs its stays in, but as soon as I start hitting the grass it just goes blah...and feeds out 1 to 1.5ft. At half revs I could go a minute or two before it inevitably failes and feeds out line. And, trying to feed line the proper way, with a tap on the ground, leads to waaay to much line feeding out. Again, seems like the spring isnt giving enough resitance.

I was using it today when the face plate (sorry I dont know the official name) wore through and the spring came out (which I found and retrieved). I've worn through a number of those parts and always just replaced it with a new one and it was always good to go immediately.

But today after I replaced it with a new one the feeding problem arose immediately. I actually have 4 spare "face plates" so I tried one and it fed out line too easily. Then tried another...same thing. Thought that maybe the new springs are too weak or something so I put the old spring back in...still feeding too much.

So I'm stumped. A quick look at the old and new face plates reveals no obvious differences.

Pictures below of the old vs new face plate, the spool, and the old vs new spring.

Any ideas?