Scripts interrupt after different time


Since a few days I have a little problem with the scripts in my openhab.
I am working on openhab 1.8.3
After a few hours (always different) all the values from the scripts do not change anymore. They will have the same value until i will restart the openhab service. After the restart, the scripts will be working again for some time.
But all other sensors and values, like Netatmo or Astrobinding are working and will be updated correctly.
Only the values of the scripts are freezing and will work after a restart of the openhab service.
Have someone a idea, what could be wrong?