This can only mean that you did not actually save the project at 1:30. Maybe Cubase was already in a freeze-crash state, and you didn’t realize it, or it might have been user error. If the file had been saved it would have been there, and that, itself, has nothing to do with the auto-save function.
Auto-save does not happen when the transport is running, nor if there are no changes to the cpr to save, so had you saved the file at 1:30 there would have been no auto-saves after that.
It is unknown what transpired in your case with the info provided, and it sucks to have lost work, for sure.
See my post here also