Click/drag on the FX blocks that appear after the amp and move them to appear before the amp.

Another thing you can do is MOVE the empty FX blocks (the dots or nodes). Helpful if you don't have access to HD Edit.

I find it easier to do this than to move the Amp block which, as you describe, has a habit of best guessing where it thinks you want it.

It's most/only useful when you want two parallel paths, with a number of pre- and post- FX in each path. You found (as I did) that the POD HD is reluctant to let you add more FX to the parallel paths over what was already there. It will let you do it, but the normally intuitive control goes out the window.

Example:-

I have a patch with A and B paths.  Currently it looks like this:-

Guitar - Comp - Empty Node - Empty Node - Empty Node - A/B Splitter -

A Path - DDelay - Amp1 - Mixer

B Path - DDelay - Amp2 - Mixer

Post Mix - Empty Node - Empty Node - Looper - Output.

I would like to add an OD to Path A

I would like to add a Filter to Path B

If I create either of these effects outside the paths (either pre or post mono path) and then try to move them into the A or B path, what actually happens is they displace whatever is already there  i.e. one of the DD's will end up in the mono path. Equally if you move the Amp it will displace the DD then end up in the A/B split (removing second amp) or if you move in the post direction  it will go straight to post mix mono (removing second amp).

I know it can be done because I can see other patches.

I found that moving empty blocks does not displace FX in the parallel path. So now I move an empty block into parallel path, then just edit that block in its new position.