This is quite common and it's becuase of the way Myriad recovers information in this situation.
To keep Myriad/Scoop/AutoTrack etc. running as fast as possible, we store the title and timing information in 2 places - one is in the WAV file itself and the other master copy is stored in the CartsXX.lst files. When you scroll around the Audiowall we display the information from the Cart List files becuase this is much faster to read.
When a user deletes a cart, the file is deleted and the relevant information is blanked over in the Carts List file.
When you then restore the wav file, Myriad doesn't know that the cart is now "back" so doesn't show the title and timing information in windows like the Audio Browser and the Jump To Cart window. However when you then view the cart on the main AudioWall window it magically appears in front of you. This is becuase at this point Myriad "sees" that there is seemingly blank cart but that has a WAV file. It therefore re-imports the information from the file and writes it back into the master Cart List files. Afterwards you can then see the cart in the browser and the Jump To Cart window as usual.
To fix this issue with lots of carts, you can either just scroll up the audiowall over the affected areas which will then detect and import each cart in turn, or you can run a report in Myriad Manager which finds carts with incorrect lengths or are missing and re-imports them - Click Run a Custom Cart Report and then select the options to correct this issue - that should resolve the problem for you (See picture below)
As a follow up note, In Myriad Manager you can view the Directory History report and this will show you who deleted the audio and when so that may help find the culprit 