Lost Garageband Recording After Saving

I have a recurring problem on Garageband on my MacBook Pro (2015).

Every now and then after recording a podcast episode, I'll click "Save As," rename the file, and then click save.

But then when I go to the saved file, it says it's only a few hundred KBs and nothing is there.

I'll go back to the Garageband recording and I can see the recording and see the audio lines, but I get an error message and nothing plays.

Does anyone know what is happening here and how I can avoid this moving forward?

Also, is there any way to recover the lost recording? I can't find it anywhere on my computer and I'm desperate.