LinkedIn Cache problems effecting a Link Preview
Below is an example of a post I recently shared on LinkedIn. You can see it pulled the thumbnail and description however this was the old information. Left post incorrect / right post correct,
In order to stop the cached content being pulled through you need to add a query string to the end of the URL.
https://www.smartclean.net/ is pulling in old content for the thumbmail and title as the post has previsouly been shared on LinkdIn previously.
Add query string to the end of the url https://www.smartclean.net?1
By adding the query string the post information wont be cached by LinkedIn and the URL will still resolve to the original URL.
Once you have added the query string you can then remove the query string, leaving your original URL. LinkedIn will then have the up to date Open Graph tags.
Udpated method as of 4-July-2018
LinkedIn has launched Post Inspector. You have to do the following to clear LinkedIn Preview cache:
Step 1: Visit https://www.linkedin.com/post-inspector/
Step 2: Enter your URL and click on Inspect, You will see the updated preview image
Step 3: Now try sharing your URL on LinkedIn