You are missing the donation id to view this donation receipt error

I feel like I’ve tried everything to make this message go away. Fortunately, the donations work and they go through and the funds hit the appropriate accounts. The emails send to the donors. I even hired someone on Fiverr to look into my caching plugin to make sure it wasn’t blocking anything and that’s all cleaned up. I’m at my whit’s end now. The receipt just will not show up after they’ve had a successful donation. Everything I’ve tried still lands me to this message. And not just me, I’ve had others give donations too and they get the same message.

Can anybody help me?

The page I need help with: [log in to see the link]