OpenGraph image is not functioning properly

[OpenGraph](https://beta.nextjs.org/docs/api-reference/metadata#opengraph) support is set up [here](https://github.com/helium/network-explorer/blob/133a61dc9f4718f638fe6bc447d269f867a45ed1/src/app/layout.tsx#L28), yet the image is not loading properly when sharing https://helium-network-explorer.herokuapp.com in messaging platforms:

On the other hand, the `/og.png` file that it's linking to is actually available: https://helium-network-explorer.herokuapp.com/og.png

Not sure what needs to change here to fix it but that's why this issue was created.