This is a very strange problem, I have reproduced it a couple of times over the past couple of days so it's real;
• tiff file opened in Photoshop from PM6
• retouched in PS, flattened and saved
• save as jpeg from PM6 results in the unretouched image being saved out.
I use the save as function daily in PM5 and have never seen anything like this. I can't begin to imagine what's going on.
Mac OS 10.13 The image files are on a server, not local drive.
First screenshot is the retouched file in PS - the retouch is nice and obvious! Second one is the view in PM6 following save as jpeg with a filename change. Last screenshot is the same process in PM5.