Hi Claudio,
If after verifying the port settings as suggested by Jarek, and testing with both auto-negotiation on or hard coding the port settings, the issue continues to persist, please run extended diagnostics during a scheduled maintenance window (if possible). Use the command: "run diagnostics extended". Please note that this command will reboot the switch to perform the hardware diagnostics tests. Once the test is completed and the switch is rebooted, you can use the "show diagnostics" command to check on the result of the diagnostics.
Please let us know if you have any questions.
Thank you.
Best regards,
Andrew