LinkedInBot/1.0 fails to make a handshake with your server and that's why it can't connect to grab page's Open Graph content or image.
You probably won't find LinkedInBot/1.0 requests in your access log. Then you need to allow HTTP access for LinkedInBot/1.0 (and provide http url for image in OG and access over HTTP to images).
LinkedInBot/1.0 uses Jakarta Commons-HttpClient/3.1 which outdated and not supported for a long time. I'm assuming it fails to access most of HTTPS websites with key sizes >= 2048 bits.
I hope devs from LinkedIn are going to fix this issue soon.
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