Preview Image In Fb Messenger. Open Graph?

I have started communicating a lot recently via Facebook messenger with my customers. I am constantly sending them links to relevant product pages via chat. But in the preview 95% of the time it just shows our main logo of the site (which looks horrible zoomed in to fit the preview box) instead of the main product image. I have noticed that if the product has a second image it will sometimes show that or if on a content page it may show an image from that page. Why is it not showing the main product image in the preview for all product links I send? Is there an easy fix for this? I have about 14,000 products so going through 1 by 1 isn't really an option.

Default Social buttons add-on can show open graph tags.

Default Social buttons add-on can show open graph tags.

I have a share button but it too only seems to put an image if there is more than one image and it's never the product image. Even if it did work this wouldn't be feasible when chatting with a customer though. Tried the default social buttons and they have the same results.

We have open graph module.

https://www.ecom-labs.com/ready-to-use-add-ons/cs-cart-open-graph-add-on.html

But at the moment you can specify images for products only manually

You can check open graph image:

I guess I just don't understand how it all works. Especially since if the product has a second image it will show that in the preview but for whatever reason it won't show the main product image.