Resize multiple table cells inverted
 

I just had a bizarre issue crop up that now seems to occur globally in multiple documents.

If I create a table, then double click and select multiple cells, resizing using the top and left side anchors scale the opposite edge in the inverse direction. For example, if I have 2+ cells selected, and drag the left-anchor to the left, the right edge of the selected cells extend to the right.

The right and bottom anchors work fine, as do all the corners.

What on earth is going on?