I've written out my full issue in the lsp-mode repo: emacs-lsp/lsp-mode#2646
But I'll summarize here as well. Using solargraph as an LSP backend in emacs, I can't get it to grok files that I require that are outside of the workspace tree. Files in gem dependencies that are declared in my Gemfile.
I'm allegedly running solargraph under bundler. I know very little about that setup but I can perform any debugging step you think might be helpful.