I just noticed that the focus TAB shows wrong HFR values. The HFR values detected in the picture are around 1.3 but HFR reported is 2.46.
Interestingly, the HFR reported in the Summary Screen appears to be correct, it's been around 1.40.
Your display units are arc-seconds - I can see this in the graph label ("). You set this in the settings tab. If you change that to pixels that will hopefully "fix" it. The display units only affect the focus parts of the screen - and not the fitsviewer. One of the things I need to do is get round to implementing a few things in fitsviewer, and this is one of them.