I have no idea what operating system you are using.
I had a fresh look at zyGrib version 8.0.1 on my
Linux box and found a strange error.
What zyGrib calls "home" in their file dialog is in reality "/home/thomas/".
If I start with root click on first "home" and then "thomas" the dialog calls it just "home".
So if you have a path /home/sailing/navigation/gribs in zyGrib you must point the grib
plugin to /home/thomas/sailing/navigation/gribs. If you use the same path in the
plugin as in zyGrib you will indeed point to a different directory.
I have use zyGrib for years without noticing........!!
Thomas