Multicam edited clip suddenly completely wrong inside my project

Hi, I have a multicam clip with a bunch of camera angles that I edited in a project — picking angles 1, 2, 3, and working my way through a concert. I then added a new angle into the original multicam clip, aligned it with the other angles, and when I returned to my project, the whole thing has all been completely messed up. It seems like my new angle might have been longer than the others, and so perhaps it changed the overall time "offset" of the thing? Suddenly, in my project the video starts way too early and all the edits are in the wrong places. Deleting the new angle does *not* fix it, and I'm freaking out that I'm going to have to completely redo the whole project. (Of course, I only noticed this happening after it was too late to Undo the changes.)

Does anybody have any idea what I can do here? I just want to roll the whole multicam clip back several minutes, but there doesn't seem to be a way to do that.

Just to clarify, the multicam clip is still correctly synced to itself. The problem is that where the project previously started at the beginning of the concert, now the project is using video from many minutes earlier, as if the whole thing was shifted backwards.

Help...

Delete render files, delete preferences, reboot?

Thanks, I tried deleting renders/prefs and rebooting, but no change. It's like the whole video became offset by about 4 minutes. 

I can repeat the problem by going into the multicam clip and moving one of the videos WAY early, extending the whole clip backwards; then in my project, the whole video is shifted WAY early as well. But I can't figure out any way to similarly move the whole clip WAY later... This is so crazy.

Can you open a backup of the library from before you added the angle? By default backups are stored in ~/Movies/Final Cut Backups/<library name>/ You can also use File->Open Library->From Backup
support.apple.com/guide/final-cut-pro/re...ary-ver85d95b8a9/mac

YES! A backup is the answer! Wow, thanks so much — I guess with enough sleep deprivation, the obvious solution becomes totally invisible.

It does seem kind of crazy that Final Cut can get so easily confused... but thank god for backups, and for wonderful people who remind you to use them. Thanks again.

When you added the new clip it's likely you shifted the start point of the multicam - You can see this if you use the position tool and drag a clip inside the multicam to the left - it'll push everything to the right. When you move clips inside your multicam,  it effects your edits.