Very long time to open files

LibreOffice 5.4, 7.1.8, 7.2 on W10 Pro 64 bit, 16 GB ram on lenovo PC i5 2,5 GHz takes several minutes to open a file since some days ago. I can’t recall wether I did something special before this happens.

Have you clicked Start menu - Power - Restart since Windows update on second Tuesday of the month? Note: not power off as that defaults to hibernate.

Thank you. I don’t understand exactly your reply. Which is the update number? I solved restoring the laptop with a previous disk image. Another laptop with same configuration didn’t experience this problem.
Than you!