After a few days of trying to figure out why my Printful products would not sync on Woocommerce, I found a solution that worked for me. Follow the below steps.
In your hosting account, go to /wp-content/ and rename object-cache.php to object-cache.php-bak
Printful mentions removing cache plugins on their website, but there is no mention of this file. I was able to find it through turning on debugging logs and searching for the errors on Google.
I’m using Godaddy as a host.