Edeliver upgrade rolling back after restarting server

I’ve been having a weird issue with one of my apps. When I run:

mix edeliver upgrade production

The production app is upgraded and it works perfectly. However, when I subsequently run:

mix edeliver restart production

The changes are rolled back to prior to the upgrade. I’m no deployment expert so I figured I’d ask around here to see if anyone knows a fix?

Also, I should mention that when I check the production server version:

mix edeliver version production

The version is the same as the upgrade I just did. So it’s the right upgrade but the code that was upgraded is no longer there?