GitLab next: cannot switch back

Summary

I have switched to: GitLab next but I cannot switch back ( It allows me to switch/choose version but still not returning back to 11.11.x version )

Screenshot_2019-06-13_at_12.56.16

Screenshot_2019-06-13_at_12.56.21

When I switch back -> only differenece I can notice is that "Next" is gone, but help still shows the same version.