Unable to load video playback and recording issues on iPhone with iOS 18.1

Issue 1: I can not play a video from Oct 2023 on my iPhone. It popped up a notice as the title above. I purchased 200GB of Icloud+ and it used 97GB of all. I am not sure but it happened when updated to iOS 18.1 recently. I already checked for the Q&A but it seems not to be working at all.

Issue 2: I recorded a video but not showing in the photo library, just a black screen with a playback bar. I changed the camera setting to 720 for a lower resolution but it didn't work. Please find the images attached below to get a clear situation.

I can play this video on an iPad Air Gen 5, so it is not a storage problem I guess.

[Re-Titled by Moderator]