UIX don't get registered and synchronized correctly in cluster mode

Happened on playground.xwiki.org, observed after the 8.4.4 upgrade, after trying to recreate playground.

Behavior: Node1 and Node2 don't get their UIX pages registered correctly. For example, Node1 will have all the UIX registered correctly, while Node2 there will be some missing.

• Node1: http://playground.xwikiorg-node1.xwikisas.com/xwiki/bin/view/Main/WebHome
• Node2: http://playground.xwikiorg-node2.xwikisas.com/xwiki/bin/edit/Main/WebHome

Initially (02/03/2017) we missed:

• http://playground.xwikiorg-node2.xwikisas.com/xwiki/bin/view/XWikiOrg/UI/QuickSearchUIX
• AdminUIX and some others
  Users were not able to see the Drawer entries (Indexes) or Watchlist menu entry and the Search menu entry.

Today (07/03/2017) we are missing some org.xwiki.platform.panels.Applications entries from the Applications Panel from Node2, while Node1 was displayed correctly, see

The temporary fix is to go to the pages:

• http://playground.xwikiorg-node2.xwikisas.com/xwiki/bin/edit/Dashboard/WebHome
• http://playground.xwikiorg-node2.xwikisas.com/xwiki/bin/view/Help/
  and resave the pages, see