Timelapse nowhere to be found

Hello, so today I was recording an important timelapse that ended up being a little over 30 minutes. I set my iPhone 15 Pro on a tripod, carefully making sure it was the perfect angle. Before recording, I made sure I had ample storage as I knew I would be recording a time lapse for a while (I had 64gb of my 256gb remaining, which is more than plenty). I then started recording and proceeding to do my tasks while the timelapse recorded. I checked in on it about every 5-10 minutes and it was recording properly throughout the entire process. Once completed, I pressed the same button I used to start the timelapse with the phone unlocked. The timelapse stopped recording as expected and everything was going smoothly... until I opened my photos app to see it was not there. Normally, I wouldn't panic, but this video was extremely important, and I could be fired for not producing this one-time video. As I cannot replicate what happened in the timelapse, and I did everything properly, I am deeply disappointed by my experience with my flagship iPhone.

Other valuable information:

• I am on the newest public release of iOS 18.1
• My phone has never had problems with this before
• My phone was charged (not charging though) and was in a room temperature (70F) environment during the recording
• It has been several hours since the recording and has still not showed up
• Turning on and off the phone has not resolved the issue
• I checked my files on a computer and the IMG_#### seems to be missing, like the video was produced but disappeared due to some Apple issue (see attached image). It would've been IMG_4489.MOV.

At the very least I want to know what I can do to prevent this from happening in the future and to make you all aware of this potential software error. Thank you.