How do I troubleshoot the buffer contents not updating anymore for a custom formatter?

[Philogy]

I have the following configuration for my filetype & formatter:

ft("solidity"):fmt({
  cmd = "forge",
  args = { "fmt" },
  stdin = false,
})

It worked until recently and all of a sudden stopped. The formatter is still being run, my view of the file's contents in neovim just isn't being updated after the formatter is run. This is just an issue for this formatter my others are still working. I know the formatter is being run because when I alt-tab away and back to the terminal where neovim is running the updated file is shown.

Any help is appreciated, thanks!