Megabonus Extension - issue with content scripts - often won't load

Good day!
We have problem with the extension load in the Firefox browser:
After installing the extension, the extension works, but if you click on the links inside our partners (for example, aliexpress.com, www.aviasales.ru), or use the refresh page (on the partner websites), then all files related to changing the content disappear in roughly 50% on cases.
When using the extension, in order to understand whether the extension works, make sure that there is a red Megabonus cashback activation panel at the top of the page - screenshot below:
http://joxi.ru/p279LbJIKL6Eer
The question is: At some indefinite moment, the main content.js file is not loaded into the browser - see screenshot below:
http://joxi.ru/MAjoMb6IjdGLjr
Found such a problem in the “Firefox Developer Tools,” Debug tab, where you can track down the non-periodic exhaustion of the file.
Manifest version of manifest_version: 2.
The file is connected via content_scripts.