I'm not able to duplicate this at all on my Windows 7/Premiere Elements 12, Mutu.
Can you be more specific about what you're doing?
Which Publish & Share template did you use?
When I returned to Publish & Share, after outputting a Work Area Bar Only video, "Share Work Area Bar Only" was NOT checked until I checked it. When I checked it, only the Work Area Bar segment output.
What happens if you uncheck this option and then re-check?
This is interesting. I'm now pretty sure I've traced the "bug"...I was using "Mobile Phones and Players" with my own preset (if I recall it correctly, original preset was "Apple iPad Widescreen High Quality" which I customized a bit).
Tested now the other presets under the Mobile Phones and Players/Apple iPod, iPad and iPhone, and they all have the same behaviour: "SWO" stays checked after rendering but the file size&duration shows that it will render the whole project if I hit the Save-button.
Next I tried rendering same clip with "Computer" presets (customized a preset from "AVCHD/MP4 - PAL DV Widescreen") and surprise, surprise! After rendering with "SWO", next time I went to Publish+Share and selected same template, "SWO" is no longer checked. So it's some kind of refresh problem with Mobile Phones and Players templates I guess?
(Sorry for my awkward english, it's not my native language...)
That I can duplicate, Mutu!
So you have definitely found a bug in the Publish & Share/Mobile Phones and Players templates.
Since what you described can be seen in at least Premiere Elements 10, 11, and 12.1, I am not sure if this is some sort of Adobe built in feature plan or what could be categorized as a long term unavoidable and/or overlooked design "bug".
What you observed in Premiere Elements 12.1 Publish+Share/Mobile Phones & Players/"Apple iPod, iPad, and iPhone"/"Apple iPad Widescreen High Quality" is also seen in at Premiere Elements 11 (same route as 12) as well as in Premiere Elements 10/Share/Mobile Phones & Players/"Apple iPod, iPad, and iPhone"/"Apple iPad Widescreen High Quality".
Whatever it is appears to point at the check box next to Share Work Area Bar needing to be "refreshed" for each of these selective exports of the Timeline content.
Did not you see this matter in Premiere Elements 11 when you were using that instead of Premiere Elements 12.1?
As I mentioned, I rarely use the Share Work Area Bar Only option, so I guess I never noticed it in PrE 11. But as I now know it's a bug, restriction or feature (or whatever you want to call it), I consider this case closed. Thanks anyway.