Thank you for the proper details, and for the examples. After a few tries the search indeed got stuck, or reacted very poorly.
I did a direct investigation via SFTP, and after some time I believe I have found the cause. In one of the latest releases I have built in a function to filter product which are invisible or set to visible on catalog only. When I disabled this new filter, the search started to work normally again. I guess this is because of the fact on how WooCommerce stores this visibility data.
Luckily this is not a vital function, so I could simply disable it. Moreover I just read the update notes for WooCommerce 3.0, it seems like they are changing this visibility feature from custom fields to taxonomy terms, so this will be resolved differently in a future release of the search – and has a major performance advantage.
Please test the search now, I believe the issue is gone.Best,
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