I use Lineage OS on a Motorola G4 plus phone. I have Google Play installed and I can install and update all kind of applications (like Stack Exchange for instance).
I can also install Firefox but only the version 59.0.2. According to the Mozilla website the current version is 60. Until I updated Firefox manually (using side loading) the Firefox website warned me that my Firefox version was outdated (which it was).
Again Google Play does not show any issue on my phone. Other applications are installed normally and updated on a regular basis, even after finding the issue with Firefox. I tried to delete the data of the Google Play application on my phone, it did not change anything.
Do you have any idea why Google Play is offering me an older version of Firefox? Does anyone have the same issue? Could this issue be linked to regional or device restrictions?