I recorded it on my Samsung S20 mobile phone. I think what might be the issue here is that the clip is HD, while I'm trying to make a 4K project.  The other clips I'm using are 4K. I've attached the clip info.    

When I preview a clip from the library (Right-click preview) the clip plays correctly sized till the end. After that the clip goes into a zoomed mode, unlike the first preview and I can't reset this zoom. https://youtu.be/Vf-Htbsrq6o Anyone else experience this? Its a 4K clip and the issue appears on landscape videos, not portrait.   ...

I am experiencing an error icon on my timeline. Not sure what the red block means (see attached pic). What is happening is that the video preview in the main timeline is not working, its basically frozen. What could this be?