3D animation video of the house in the forest

I hope everyone is well. So I have been working on this model for the last 2 days. I have talked about its 3D design and the process of making this video in my previous two posts. So the video of the end is made. I have changed a lot in the model. But at the end of this video I had some problems. Because if you watch this video, you will understand. I looked for the cause of this problem in various places but I did not find it anywhere. I do not understand why. Video editing, output setting, preview are all fine but I can't find any reason for the output to be like this. I'm still working on it. It is not possible to re-render it because it took me 5 hours to render it (1280 x 720) in medium output quality. I don't know when it will end if the setting is fixed and rendered again. However because of this problem I came to know about this kind of problem. And how long does it take to make this kind of video in this software, how is the output? I did everything for this. I hope I can do the next one better. Thanks.