VFR stands for variable frame rate. This is footage taken from a screen or camera that is not recording in a static frame rate such as 24, 30, or 60 frames per second. A good example of this is a screen recording or a video chat recording, from tools like Zoom or Google Meet.
When bringing this footage into Premiere Pro without transcoding it into a static frame rate, your footage will likely have visible damage.
This issue can be solved but does take an extra few steps in the editing process.
Import your footage into Premiere Pro
Find VFR footage
Select clip with the potential issue
Properties from the menu
See the last line in the properties inspector
If footage states
Variable Frame Rate Detected then this footage will likely be damaged at multiple parts in the clip
To correct this we need to transcode the footage
Right-click and click
Open in Finder
Once the clip is found – launch Adobe Media Encoder
Drag clip into Media Encoder
Select any format you'd like, for my example, we will be using h.264