There was a problem in the database: not all contributions waiting were visible in the list. That is fixed, as I asked the server to check the tables, but while doing that it gave me a warning message about the fact that the vehicles table list went from 261012 to 261011 in the process.
Either someone deleted a car while that was done (but it is not in the delete log), or there was an error, or a car was lost... Maybe I should offer a reward for the one who finds it?