I am getting an error where some of my text looks outlined when I save as PDF. This does not happen when I export as JPEG or PNG. Please see images below for the result and my PDF settings. I am on Photoshop CC 2015.
You may try an rest the Photoshop preferences back to defaults and check if that helps.
Refer: Preferences in Photoshop
Also, you can update the Photoshop version to Photoshop CC(19.0) and check if that helps.
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