I didn't even get that far, none of my photos will upload within a text post at all, whereas previously I had no problem with this at all.
I suspect you're using the "New Post" tool in the grey admin bar: that tool is meant for quick posting, so it does not include all the options that are normally available. More important, it's buggy: your content may disappear, partly or completely (users have been complaining about this for months, and so far WP has found nothing to say or do about it).
So (if my suspicion is correct), don't use that way to create posts: use Posts > Add New in your dashboard sidebar.
To correct your latest posts, you can go to Posts > all Posts, edit each post, delete the image and re-insert by clicking the Add Media button, and also change its post format from Image to Standard.