Damn, Mash support is fast. Here’s what they said: 

„Thanks for reaching out Heather. And appreciate you using Mash. I just took a look and was able to create the invoice. It might have been a hiccup in our system at that time. If you get any more reports of this, do tag us as would be interested to see if there is a specific instance causing issues (like a specific browser). We haven't had any other reports, so think all is fine.”

Y’all lemme know if you try and zap ⚡️ on my site with Mash and it doesn’t work 💪 

 Awesome work by Mash then 😄 

Zap worked! Invoice loaded nice n quick. 

 Yay!  Thanks! 🙏🏻