Timing chain tensioner not reinstalling?

Hello,

I removed the timing chain tensioner because it was leaking oil and now, I can't reinstall it.

It does not go fully back into the bore by about 1/4" or so. It is pushing against the timing chain guide slipper, but it does not move it back inwards to clear the last 1/4".

Tensioner is fully compressed and locked.

I can feel the timing chain guide slipper with my finger, and it does not move.