First time I experienced this throughout my work with Miro and it makes work annoying.
I cannot manipulate object order (send back or in front) when they are in a defined frame, but I can do it if the objects are out of frame. See two pictures: two circles in the frame - I cannot manipulate order. Once the same circles are out of frame - I can manipulate order.
Is there an issue with my board setting or is this internal Miro functionality? I tested with different boards and got the same results.