I'm creating some configurable products on Magento 2.3, I set color and size as configurable attributes. I need to set for each color a specific product images. When I save the product with the configurable option it takes long time (about 2-3 minutes), after that I get a 503 error, the product is saved but the procedure takes alot of time. When I create the configurable product with same attributes options but without images the saving time is normal.
I try to edit php limit memory, switch to production mode, switch from built in to varnish cache, no result, it's faster but when I upload some images it's very slow.