this.get(...).then is not a function when using init: ember.js

I am using init() in my component to load some data for a dropdown. On refresh it works but when I leave the tab to another tab then come back I get the following error: index.js:143322 Uncaught TypeError: this.get(...).then is not a function

This code is in my init function and I suspect it has something to do with how ember.js renders but I am struggling to figure out how to make it work. I tried using the other lifestyle hooks but none of them worked.