Good morning,
Setup
- Windows 10
 - Edge
 
Issue
- Login in to RMM7 Beta
 - Select a message which shows a Vertical Preview to the right.
 - Click to select Horizontal Preview > no Preview shown
 - Problem seems to occur due to horizontal bar being right at the bottom, if dragged up a Preview is visible.
 - After setting horizontal bar should I switch to Vertical Again and back again the problem will re-occur.
 - Selecting a different message after selecting Horizontal Preview doesn’t result in a Preview showing.
 
It’s like Horizontal Preview position is not stored when using Edge. FYI Indexing was not active…
I tested with Firefox 61xx and it seems OK with the above and Preview is not lost.