Confluence Cloud - side page tree missing

Problem:
We, at InTENSO (Atlassian Partner), are facing problem that side panel (page tree) in Confluence Space is missing for anonymous access.

Background:
1. When logged in, everything is fine.
2. When accessing space anonymously, the side panel is completely missing - not only page tree, but all the panel content (including space name and icon).
3. The problem is present only for one space https://intenso.atlassian.net/wiki/display/FLO/TestFLO
4. Settings compared and set as in other spaces (where everything is fine, for example https://intenso.atlassian.net/wiki/display/SPFJSD )
5. The problem is gone, when anonymous gain permission to Add Pages (which is
now set, we only added temporarily restriction for editing)
6. some users icons are missing too (for example when selecting them in restrictions menu)