files on the nas such as xlsx, odt, etc load very long, when ich try to open it by nautilus (gnome) the first time. the second time the files open fast, but after inactivity the files open slow again. The problem is not with pdf files.

On the other hand when I open librewriter, librecalc, and try to open the sames files, the files open very fast the first time; and even inactivity the files open fast

Now why open by nautilus ist so slow? Is this a bug?
Thanks in advance.