Using Pages 5.6.1 in OS X 10.11.5 and 10.11.6
I am experiencing the same problem as Tim and hing9841 so I will try to explain step by step what I am doing that produces this strange behavior. I've taken screen shots with the invisibles shown, however there are no rogue characters in between the formatting as you will see, so I really don't know what is causing this other than it being an overlooked issue during program development.
Right now I am editing the notes I took in class. I have two blocks of text and I want to place a title (in bold) in between these paragraphs, with a line of whitespace above and underneath it so I press Enter twice. Which produces this:
As you can see there are three pilcrows ¶ of which one is highlighted in green, which is where I want the bold title to be. However, because the pilcrow ¶ is highlighted the whole line is highlighted, so as soon as I start typing this erases an entire line of whitespace between my two blocks of text:
At which point I have to reinsert my line whitespace after I am done typing the title (and remembering to press command + B again so the bold formatting iasn't attributed to the next line as well.)
Now, why bother preemptively creating my whitespace, why not just press Enter once above the paragraph I want my title to be and start typing? That produces this result:
As you can see the pilcrow ¶ (and as a result the whole line, just like in the other example) is still selected. HOWEVER, when I start typing now, not only will the line I just created be deleted, I receive the same formatting as the paragraph below, and the bold I had just selected disappears (note the red box selection, the text is reset to "Default*" from "Default*" in the previous picture). Obviously this is due to the paragraph break/pilcrow ¶ being selected with the text, which is exactly the problem here.
Just to emphasize what I mean I changed the formatting of the paragraph below to green 14pt text, and started typing with the pilcrow selected after pressing command + B:
You clearly see that it just copies over whatever formatting I have in the text below.
The issue here is that when changing to bold/italic/underline at the start of a line that contains no text (either via keyboard shortcuts or by pressing the B/I/U buttons in the menu to the right, Pages selects the line WITH the paragraph break ¶. I have never seen this behavior in neither Word nor Open/LibreOffice, surely this is not working as intended. As Tim stated, this severely interferes with workflow and is quite honestly infuriating as the only workaround is to press an arrow button or manually click somewhere so the pilcrow ¶ becomes unselected, and I can then type my text without having an entire line erased.
I would like to re-emphasize that this happens irrespectively of using keyboard shortcuts, manually pressing the buttons in the menu to the right, or going through Format > Font > Bold/Italic/Underline and so on.