All these captions should be in a single thread, but in their own frame. You can do it, if you change the keep options of the used paragraph style that the paragraph starts in a new frame.
The numbered order comes then from the order how these frames are linked.
Otherwise it is difficult in InDesign to get the correct numbered order.
Thanks for answer. Captions are in a single tread and in their own frame, but as You see the numbers are now in the wrong order. I wish that the order is from left to right and from up to down. How can I fix it?
I finally did it manually, page to page. I removed all image text captions and put those back in right order. I think, there is no another way to update them.