Auto import doesn't work in some cases

[Akhristenko]

Your environment

haskell-language-server version: 1.4.0.0 (GHC: 8.10.7) (GIT hash: 253547816ee216c53ee7dacc0ad3cac43e863d30)
Tool versions found on the $PATH
cabal:          3.4.0.0
stack:          2.7.3
ghc:            8.10.4

Which OS do you use: Ubuntu 20.04
Which lsp-client do you use: VSCode

Steps to reproduce

• create new project with stack and latest resolver (LTS 18.10 for ghc-8.10.7)
• in this project add mtl to dependencies of executable
• build project and open Main.hs
• in end of the file typing rc = runC, invoke autocomplete and select runCont from Control.Monad.Cont. After that line with import Control.Monad.Cont (runCont) will be added on start of the file.
• in end of the file typing c = con, invoke autocomplete and select cont from Control.Monad.Cont

Expected behaviour

hls modify import list to import Control.Monad.Cont (runCont, cont)

Actual behaviour

import list remain import Control.Monad.Cont (runCont)

[Akhristenko]

After doing a few experiments, I noticed some patterns.
Auto import doesn't work in case, when vscode insert snippets when use autocompletion. i attach screenshot illustrated this case.
If i disable this feature auto import work correct.

[michaelpj]

We don't provide snippets any more, so I think this may well be fixed by accident