I will try
Customer changes the tape every day. All backups go to one single tape as fullbackups. Tapes will be overwritten after a week.
Works fine if I only have one job and create a new media set for every session in the media settings.
But if I have more then one job linked to the tape job, it overwrites the first job, so I only have the last job on tape.
One of the job only runs weekly, the other runs daily, maybe that causes the problems.
Most other backup programs have a retention setting for appending jobs to media. So if the next job is in the appending retention period, it will append it to the tape. If not it will ask for a new tape or it will overwrite the tape if the write protection is due.
In Veeam I can only select append until tape full or always overwrite even if the tape has a fresh backup on it. For users without librarys that won't work very well.