Hi l.will,
Thanks for bringing this to our attention! I was able to reproduce this when trying to click and drag to select multiple cells if the table’s column/row controls sit outside of the editing frame of dynamic panels and repeaters. This will also happen if the controls are in the negative regions of a page.
As a workaround, if you move the table’s controls in the editing frame, you should be able to select multiple cells as you’re used to. Alternatively, you can use [SHIFT] + click to select multiple cells as well.
That said, I’ve gone ahead and have filed this with our respective teams here at Axure HQ!