FileNotFoundError error

I have developed a different prefect flows that accesses a mapped drive to read various Excel files. The flows were working perfectly until a couple of days ago when they were executed from Prefect Cloud. The flow now fails with a FileNotFoundError:

Finished in state Failed(“Flow run encountered an exception. FileNotFoundError: No such file: ‘Z:\Monitor automático\MONITOR COPACKING.xlsm’”)

Interestingly, when the flows are run locally, the error does not occur. What could be the problem?