[Plugin: Add Link to Facebook] Working but small issue

You can uncheck the option ‘Do not execute shortcodes for texts‘ to fix your problem with the image captions, but be sure to check if it doesn’t conflict with other plugins, because it sometimes does.

The ‘Read more …’ on Facebook is just text, because Facebook doesn’t allow us to use links (or any other HTML) in the link status text.

Actually I am quite sure that this should work, since I am using this on my own website and to be very sure I just tested it successfully too. Please note that changing this option does not alter existing links (maybe obvious). You can also try to disable the option ‘Do not execute filters for texts‘, but disable the other option and be even more careful to check if there are no conflict with other plugins (the whole reason these options are checked by default). Your problem could originate from a conflict with another plugin too.