You can have several different things.
One is the new GFCI is bad, but it is also very easy to get the wires confused and that keeps it from working.
Was there a label on the box for the new one? That might let you review and look carefully at how it is wired. Possible user error is one I always have to admit to. We humans do that soort of thing!
The new one CAN be defective, but I tend to assume not until proven!
So this drawing is how the power comes to the GFCI and where it goes beyond. Read it like a road map?
Click this snip to get a better view!
This shows some possible options and you may have them or not, so if nothing there ignore and move on!
What you are looking for is a "leak" from the power to ground. If the oulets are all where you can reach them easy enough, I might favor unplugging anything in those outlets. That removes faulty things like power cords, etc.
But if the GFCI still won't hold, you may have to go to each outlet and check for a problem.
I might go to the exterior outlet as they can get wet, etc. That one at the bottom may be good place to start if easy to reach? If you take the cover off, there will be a set of wires come in and a set go out or possibly two go out to the galley? The idea is to pull some wires apart to see what removes the leak/fault!
You probably don't need to remove all the wires at each outlet. leave the white and bare wires to cut the time/effort. I think just removing the black ?hot side will get it ! But DO put it back together before moving on down the line.
While there, look for things like signs of the outlet getting wet, bugs like ants making a mess to short things out, or something broken?
We are hoping it is the outside due to weather? Unless you know where you poured the water in an outlet in the galley??
Good luck with the chase as it can be simple and you open the right one the first time or it can be the last on!