Resolved for me. There is a plugin conflict between ZP and WP Rocket. Solution: on the ZP page in the right column “WP Rocket Options” unselect “Minify/combine JS”. The “Submit” button color will change from green to gray and everything should work again. Hope it helps for you. Serge
Same here. Works fine on page preview but not at all on any browser. Tried all suggested recommendations. No clue what to do next. Thanks for help. Serge
