There was a change of behaviour from Confluence 4.3.7 to 5.3.4, in Confluence 4.3.7 our body macros used to accept the INLINE output type, however due to the CSS changes that option is no longer available.

Find below the instructions on how reproduce this behaviour in our latest version, if you follow these same steps in 4.3.7 you will notice that the macro will be INLINE with the text.
In my example I used a third party macro, however that behaviour will be the same with any of our bundled body macro.

Steps to reproduce:

1. Start a Confluence 5.3.4.
2. Go to UPM and install "Confluence Source Editor".
3. Download Reporting Plugin, can be either from marketplace or UPM.
   You will also need to get a free license for reporting plugin.
4. Create a page.
5. Use source editor and add below code:

   <ac:macro ac:name="report-link">
   <ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter>
   <ac:default-parameter>content:url</ac:default-parameter>
   <ac:rich-text-body>
   <ac:emoticon ac:name="green-star"/>
   </ac:rich-text-body>
   </ac:macro> and some text here
   

6. Once you hit save Confluence will change above code as following:

   <ac:structured-macro ac:name="report-link">
   <ac:parameter ac:name="atlassian-macro-output-type">INLINE</ac:parameter>
   <ac:parameter ac:name="">content:url</ac:parameter>
   <ac:rich-text-body>
   <ac:emoticon ac:name="green-star"/>
   </ac:rich-text-body>
   </ac:structured-macro>
   <p>and some text here</p>
   

7. In below image you can see that "Some text" will be under the icon instead at the side:
   

If you try to use the same code of step 5 in the source editor of Confluence 4.3.7, the code will not be changed and the image will be displayed as this:

Workaround:

If you edit the page using the UI you can put the "Some text" inside the Report Link block, however that text will be turned into a link:

1. Editing the page:
   
2. After saving:
   

ps.: I've moved this case from a bug ticket to a feature request on a customers behalf.