Publish table to html5 -- allowed Anchored Frame 'Anchoring Postion's?

Following on from a deeeeep post earlier, I have a pared down question.

In our docs there are many images in anchored frames where the frames use Anchoring Position "At Insertion Point".

When I tried to publish to html5, these frames don't appear in the output.

We use three of the possible positions overall in our docs -- At Insertion Point, Run into Paragraph, and Below Current Line.

I simply changed the position of one of the images that didn't display and got the following results:

- At Insertion Point -- frame does not display, line before and after the image print one after the other, nothing to indicate the image should have been there.

- Run into Paragraph -- same result

- Below Current Line -- this one works

Question -- Is this the expected behaviour? (I'm fine if it is, just want to know if I'm doing missing something here.)

Thanks!