What you're describing is often, mabye even usually caused by a saddle that is either slightly nose down, or needs to be tilted a little nose up above dead level. Yes it can also be caused by a reach that is too far, but in my experience it's more often saddle level first, then adjust the reach if neccessary.
The first thing I would do is:
1 - put your bike on a level surface, and then put a bubble level on the saddle. See exactly how level it is, or how much nose up or down it is.
2 - if you're saddle is nose down, adjust it until it is dead level using the bubble level. If it is already dead level, or close to that, adjust it so it is "1/2 bubble" nose up (in other words, just a tiny bit nose up). After you try that, if it's not right, you might try even a tiny bit more nose up. You might also have to lower the seat height a little, but do every thing in small increments and keep track of what your'e doing.
I've found that my comfort and ability to stay on the sweet spot of the saddle I use requres it to be about 1/2 to a full bubble nose up. It works perfectly for me that way. Your saddle angle will depend on your own anatomy, the saddle, and your preferences. But give the above adjustment a try before you start sliding it back and forth. My experience is that for me, keeping the saddle back a little behind "KOPS" also helps me settle on the saddle better. If I'm a little too far forward, my position on the saddle actually suffers a little too.