Widgets with the same height render differently.

I designed my widgets on an S7 to my satisfaction, now just upgraded to an S9, and tried to get my widget layout that I designed onto that, but have hit some weird problems with sizing. Most of the issues were down to me designing without size variance in mind, and I've managed to solve them. However, one issue remains and I cannot find a solution. In the attached image, the bottom two widgets are the same height, and both have a "shape" item for the border. Both border shapes are rectangular, and use a formula for the width and height, $si(rwidth)-10$ and $si(rheight)-10$ respectively. When I look at the widgets in the editor, and the results of the formula, both show 326, yet the right one is clearly shorter and doesn't fill it's space. I'm using Nova launcher and both have padding switched off. When enable the widget resizer, they both look exactly the same height. The scale of the layer in both is 100, manually set by me.

Any ideas very welcome, really want to get these aligned, as the whole layout looks naff otherwise.