We've received multiple reports that in Sketchup 2020 ComponentFinder thumbnails are being saved in top view only. Ouch!
This happens when saving through the API and also when doing a Right Click > Save As. We reported this bug to Sketchup and they have acknowledged it - Let's hope they release a fix for this soon 🤞.
Until they fix this, if you're a heavy ComponentFinder user like we are, and you want your thumbnails saved in a normal 3D view, we recommend to stick with Sketchup 2019 for now.
To get Sketchup to fix this soon - feel free to join the conversation in the forums.