Hi @whintz!
Yes, this is a known issue with Lightroom 8.3 for Windows, and you need to downgrade to Lightroom 8.2 until Adobe fixes it. It only effects some users, but for those it effects, it seems to break all exporting of photos to specific folders (both trying to export through the regular export dialog in Lightroom, but also plugins like Negative Lab pro that rely on being able to export images to analyze them).
See this thread:
I believe Adobe already has a fix in pre-release so hopefully that will be ready for general use very soon!