Since 17 july, 2017 facebook no longer listens to the parameters for picture/name/description/etc when calling the feed dialog. I can still share the page, but it uses the cached data.
Is there any way to let facebook re-crawl the page before sharing or an way to let facebook know the picture or description of the page has changed (without using the Facebook debug tool)? So my users can still change the picture and then share this page with the new picture without waiting for another 24 hours.
Use a unique URL with unique OG tags. Trying to recrawl the url whenever you share it is not a good idea, Facebook wants each URL to have the same OG tags - not different ones for different share events.
Whenever you share an url with specific OG tags, use an URL with a parameter for those specific OG tags. That is the only way as of now.