Can’t save any input into WooCommerce Product Vendors

Hi, I’m trying to run Product Vendors with my WooCommerce setup but anytime when I’m trying to save some data (email, PayPal email eg) for a vendor via Products > Vendors > Vendor > Vendor email it just refreshes the page after Update and hasn’t got any stored info.

I read something about increasing the PHP max input vars, so upgraded those from 3000 to 6000. Still no response. My developer thinks it is a plugin conflict or issue.

Does this sound familiar to anyone and might know something? Thanks in advance.