If you are a national of another country or you have residency in another country you are able to travel to that country without hindrance.
I have residency in Portugal and come and go as I please as I am a British national.
As ever, you just have to have the correct paperwork, they like a bit of paperwork and documentation now, in fact they love it!
It is like we have gone backwards 30 years or so and border checks all through to Portugal and back again…Really is quite nostalgic for me. 
I do like the French being under curfew though, makes for a very pleasant traverse through that country.