You’re polishing your blog post, adding a few Pinterest pins pointing to additional relevant information. You leave the WordPress editing screen to check out a Preview. You catch a spelling error; all else looks fine. You re-enter the editing screen, correct the boo boo, and perform a final Preview. 😱 The pins have disappeared! WhaDaFrig??!!??
You re-check via the editing screen. Gone!
Sometimes all is well. Other times you’re in pin-post hell. The fix, thankfully, proves simple.
Source: How to Embed Pinterest Pins So They Don’t Disappear