Duplicate files in Web IDE

I am working on a .ino file with three .h files. After renaming the .ino, I suddenly had six .h files. Each of the .h files now has a twin.

I’ve encountered this issue several times in the past, and I rudely discovered that deleting one of the twins via the IDE gets rid of both … so my remedy has been to create a new project and then copy/paste the files from the original project. Once I get the new project working, I delete the original project.

Searching for an easier way, I found multiple posts on this issue dating back to 2014, but I did not find any magic recovery method. Does anyone have one?