This is a site for an art gallery where I have artists that are related to woocommerce products- We imported about 400 products initially including the relationships and that worked fine. there is a one-->many relationship between artists and products
But now we find a few where the relation ship isnt set so were trying to set that up now.
The issue we run into is that when we try and build the relationship from the artist's page- the popup where we could select the product initially says results could not be found and then when we search for a product name it says "no results found"
If we do it the other way around to add the artist from the product page the buttons are greyed out
I've seen cases like yours where a plugin conflict can break this functionality, as such I would recommend that you disable all the non-toolset plugins and check again to see if the issue still remains.
If it does could you provide me with admin access to the site so that I can check on this further for you ? I will perhaps need to grab a copy of the site if needed.
If you check your trash you will notice that there is the post "Hudson, Eric" the reason why you're not able to find the Eric Hudson to At Rest, Monhegan Harbor product is because it is still connected to the Artist that is in the trash.
You will need to completely delete this in order for you to be able to connect a new post to the "Eric Hudson to At Rest, Monhegan Harbor" product.
We are currently working on improving this as we were able to identify the issue where you're unable to connect a post if the previously connected post in the relationship has been trashed.
Please let me know if this helps to resolve the issue.