Motor Trim Question

[Lil Baby]

I have a 2016 Crestliner VT with a 115 Mercury 4-Stroke. The motor will only trim just under a 1/4 way when getting up to full speed. Seems like it should trim higher than this, and was when I first got it. The other day I was at full speed and tried trimming it more and it popped up all the sudden and I was able to trim it more. I noticed it got on plane better and got a little more speed. I fished yesterday and could not get it trimmed past just under 1/4 way. Maybe this is how it's suppose to be but it seems like it should trim up more than it is. When I first got it I was able to trim it more but not much. Any thoughts?