In version 4.4.0 when i toggle repl it show blank window. So I downgraded to 4.3.2 Repl worked fine. I believe it is because of this #429 where in lua/haskell-tools/repl/builtin.lua - local job_id = vim.fn.termopen(cmd, opts) + local job_id = vim.fn.jobstart(cmd, opts) which caused the bug.
