Nautilus does not open the file

I have xubuntu 18.04.2. It defaults to the thunar file manager. I don't like this manager, I prefer nautilus. I install nautilus, delete thunar, make nautilus default, go to nautilus, try to open some file, for example. png, but instead of the expected opening of the image in ristretto, I get an attempt to open the file(loading circle) and as a result, nothing opens. If you click on the file and click "open in another application", and select the desired one the program, then everything opens without any problems. I download thunar back, make it default, but I don't delete nautilus. I run nautilus(despite the fact that thunar is the default) and all files open without problems. Please tell me how to make sure that I do not have to keep thunar? I roughly understand that somewhere thunar is registered as the file explorer for files, and when I delete thunar and make nautilus default, the default explorer does not change in this "somewhere". How do I make it change? What file edit? Tried this is, but there is no such directory and file. By the way, according to the link, the person unsubscribed that he also does not have such a directory and file. I also found an option to edit /usr/bin/xdg-mime, but so far I haven't found the necessary lines.