Resized Event Not working when upside down

I am firing the resized event when the phone orientation is turned. It works when the the phone is upright (portrait) and turned either clockwise or anti-clockwise (landscape). Orienting the device from landscape anti-clockwise to portrait works, however from landscape and turning it clockwise (portrait) upside down does not.
Can anyone elaborate or is this an issue?

If you open other app you can see that the screen doesn’t change from landscape to portrait upside down.

My guess (I haven’t used Xojo for iOS yet), is that there is no firing when the phone is turned this way. The app I tested kept the landscape display and it looks sideways when turned to portrait upside down.