Yeah, so I read through that. At no point did anyone mention a DE issue. They only mentioned a distro issue - in this case EnOS.
In order to test if it’s related to your DE, you’d have to install EnOS using a different DE than Plasma. However, as they established you should experience the same thing across Linux distros, and seeing as you are not, the DE itself shouldn’t matter.
According to your tests, using a different distro with the same device works as expected. So this is solely (as far as we can see) an EnOS issue.
It is okay to use a different distro and ask for help here, just so long as you know your issue may be unique to the distro you are using. This is a great Arch community. The best IMHO. 
For me, I need noisetorch (a noise cancellation app) for work. For whatever reason, when I had installed it while using EnOS, it just wouldn’t work properly, and I remembered that I had tried ArcoLinux and Archcraft before where it ran perfectly. So now I’m not using EnOS for the base install, but I’m using it as a secondary Repo. 
Do what works for you.