process.env.MY_VAR is undefined while it exists on the host

I am having the same issue since like 3 hours ago. Exported vars to my app on fly.io. Checked for any misspelling, console.logged the vars; console.log(process.env.[thevar]) shows undefined.

[edit]
1.159 process.env.ABC undefined
This is what I get when running console.log('process.env.ABC', process.env.ABC);
The issue stays the same after changing to newest node version

# Start with a Node.js base image
FROM node:22.6.0

Moreover, env vars where loaded via

fly secrets import -a [theapp] < .env.[theenv]

I had no such issues a few days ago.