For dumb switch wiring, that actually makes sense. In a non-neutral configuration, power starts at the light and is sent to the first box, usually over the white. You tested and found that the white was hot.
So for this to work, power has to be sent to the other box. So in the first box, the white hot would be connected to the black on the 3-wire going to the other switch. In the other switch, that black that is constantly hot is connected to the common terminal so that switched power can be returned via the white or red traveler.
Back in the first box, the switch power arrives via one of the two 3-wire travelers and then sent back to the light via the black from the 2-wire attached to the common terminal. So in the first box, I’m guessing that the black attached to the common terminal was from the 2-wire to the light.
So this seems normal to me for a non-neutral dumb switch configuration. I know that the colors used in the Inovelli diagram are slightly different, but there are not absolutes with colors, so it sounds like you are essentially wired dumb-switch-wise like the diagram.
The weird part is that the Aux works properly sometimes after repeated presses.
It still could be a settings thing. Maybe someone on HA that has had similar issues can comment.
Or maybe Inovelli . . .