Can't access any repository via ssh

I’m using official Gitlab docker image “gitlab/gitlab-ce:latest”.

GitLab 10.7.0
GitLab Shell 7.1.2
GitLab Workhorse v4.1.0
GitLab API v4
Ruby 2.3.6p384
Rails 4.2.10
postgresql 9.6.8

I cannot access any repository via ssh

"C:\apps\Git\bin\git.exe" clone -v --recurse-submodules --progress "git@gitlab.nevlabs.ru:velan/velan.git" "C:/Work/nevlabs/ВЭЛАН/velan"
Cloning into 'C:/Work/nevlabs/ВЭЛАН/velan'...
fatal: 'velan/velan.git' does not appear to be a git repository fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.
Done

Press Enter or Esc to close console...

Https works well

"C:\apps\Git\bin\git.exe" clone -v --recurse-submodules --progress "https://gitlab.nevlabs.ru/velan/velan.git" "C:/Work/nevlabs/ВЭЛАН/velan"
Cloning into 'C:/Work/nevlabs/ВЭЛАН/velan'...
POST git-upload-pack (375 bytes)
remote: Counting objects: 1318, done.
remote: Compressing objects: 100% (494/494), done.
remote: Total 1318 (delta 742), reused 1285 (delta 715)
Receiving objects: 100% (1318/1318), 334.16 KiB | 720.00 KiB/s, done.
Resolving deltas: 100% (742/742), done.
Done

Press Enter or Esc to close console...

The issue is not the ssh keys since standard welcome message appears:

Using username "git".
Authenticating with public key "rsa-key-20180313" from agent
Server refused to allocate pty
Welcome to GitLab, Мурыгин Павел!

Completely clueless here! Any suggestion how to debug the issue?