Gitlab runner keeps removing untracked files and directories

Description of the problem

I have a nodejs project and trying to get best speed from CI process. Don't understand why gitlab runner removes untracked files like node_modules.

Which Group/Project (with full path) is experiencing the issue?

Approximate date/time when the error occurred.

always

Describe what you were doing right before the issue occurred.

I tried with these settings in pipeline:

variables:
 GIT_STRATEGY: fetch
 GIT_CHECKOUT: "false"

But it didn't help, here is output:

> Running with gitlab-runner 11.9.1 (de08a4bb)
>   on frontend-core qU95Hxn6
> Using Shell executor...
> Running on core...
> Reinitialized existing Git repository in /home/gitlab-runner/builds/qU95Hxn6/0/company/frontend/.git/
> Removing dist/
> Removing node_modules/
> Clean repository
> Fetching changes...
> fatal: remote origin already exists.