High Sierra: Converted to APFS and Finder not updating available capacity
Since you asked if anyone else is having these kinds of issues, yes, I can share that almost a year later, on the current version of High Sierra, this is still a bug. You basically can't trust the available space number now. I'll leave open the possibility that someone has a workaround.

In my case, we moved 20GB of files off the boot drive and deleted another 10GB (emptying the trash immediately). The free space number didn't change (other than to actually decrease slightly. I fiddled with checking various things – Finder Get Info on the disk, also had the false number. Finally as I was staring at the number at the bottom of the Finder window (the status bar) it snapped from 47GB to 77GB before my eyes.

I'll avoid giving my honest advice for how to get this basic feature working since it would not technically be an Apple-related answer so it might be ruled as off-topic.