I have the same problem as with 3.5.0, when I install the new version it doesn't import my printer, material or profile settings from 3.4.1. I mentioned in the "New Cura 3.5" thread, but since the problem is still here in 3.5.1 and that other thread is so long, I made a new topic.
Below is the last step I tried for 3.5.0. I have since uninstalled 3.5.0 and installed 3.5.1 and even tried the steps below on the new version. Not working. I still have 3.4.1 installed and am using that, since it has all my setup.
I tried this. It did it's setup thing, but still the same as last time. It didn't import anything. It just has the default printer settings, materials and profiles. Not my settings, materials and profiles.