Prevented from exiting nvim: `"No write since last change"`

[loqusion]

When I try to exit my editor via :qa, sometimes I'm shown an error saying "No write since last change". Then, a file like the one in the screenshot is shown, with 'modified' set to true as indicated by the + in the statusline.

The contents correspond to the context lines:

It seems to indicate that the buffer showing the context lines is considered modified for some reason?

[adoyle-h]

Same problem. It creates many different unwritten buffers with one or two lines code context.