Tested on cawiki and enwiki.

1. Create a new Flow board(or go to a previously created but empty one - no topics posted).
2. Add a topic. The topic is correctly displayed.
3. Click to change the sorting order on the page - the newly created topic will disappear.
4. Click on the Browse topics - the topic will be displayed twice.

5. Add another topic - the topic is displayed. Change the sorting order - the second topic disappears and no topics are displayed at all. Switching between sorting orders does not make the topics appear.

Refresh the page - added topics are correctly displayed.