Copying more than one anchored object style text box causes overrides

[Ivo5C8D]

Hello everyone!
I am experiencing a weird bug.

1) I have a text box with an object style (the only attribute is fixed size).

2) I create another document and paste that text box in it. In the new document's object style I only change the same size attribute to a different one. 

3) When I copy and paste single or several text boxes to the new document, everything is working fine - they change size

4) The bug appears when that text box is anchored in another text box - when I copy & paste a single text box with another anchored text box in it, everything works as it should, bet when copy & paste more than one text boxes, the rest of them get this weird override bug, and the size does not change.

It is much easier to see it in my attached short video.

Can anyone explain me is this a bug or I am not doing something right?

[Ivo5C8D]

I know I can use Clear Style Overrides script to fix everything, but still this thing is driving me nuts!

[Ivo5C8D]

Here is a shorter GIF version of the problem! Same object, same style. Bug?