10.8.1 Empty branch list in merge request

Components
GitLab 10.8.1 (21a8d61)
GitLab Shell 7.1.2
GitLab Workhorse v4.2.0
GitLab API v4
GitLab Pages 0.9.1
Ruby 2.3.7p456
Rails 4.2.10
postgresql 9.6.8

After Upgrade from 10.4.x some users see empty branch list (Source branch and Target branch) when creating MR
%D0%B8%D0%B7%D0%BE%D0%B1%D1%80%D0%B0%D0%B6%D0%B5%D0%BD%D0%B8%D0%B5

They still see branches in http://gitlab/Group/Project/branches
They still can create MR from URL

i didn’t find any differences between “good” and “bad” users. both developers, both created before update.

Found different.
settings “Preferred language”
English - all work fine
also check Deutsch, Italiano - ok
български, Русский, 日本語 - bugged