@MatthewMDavis, have you tried running from the root?
For reference, rspec.vim uses @% to determine the file path. You can confirm the output by running :echo @% in Vim. This should match the path you would need to run in vim.
One other setting to look at is autochdir. You can determine the value by running :verbose set autochdir?. You’ll either see noautochdir, or the last file that set it. If set, that could be interfering.