Created attachment 120682 [details]
Cannot add a composition again after previous composition removed

SUMMARY
Clicking lower left and right corner to add a composition is very convenient and productive.
But, after these composition gets removed, the highlighting remains on the clip even the mouse pointer is far away from the clip.
Moreover, after this, clicking the highlight does not add a composition any more.
The only way I found to heal this state is to move the clip onto another track.

STEPS TO REPRODUCE
1. Place a clip in the project bin onto the timeline
2. Mouse over the lower left corner of the clip on the timeline --- (A)
3. Click the green square highlighting --- (B)
4. Remove the composition that has just been added --- (C)
5. Click the lower left corner green square highlighting again --- (D)
6. Mouse over the lower right corner of the clip --- (E)

OBSERVED RESULT
A. A green square appears at the lower left corner. NORMAL
B. A beginning composition is added to the clip. NORMAL
C. The composition gets removed. NORMAL
C. The green square highlighting on the lower left corner of the clip remains. ABNORMAL
D. This time, nothing happens. ABNORMAL
E. A green square highlighting appears. NORMAL or ABNORMAL

EXPECTED RESULT
C. The highlighting should be invisible when the mouse pointer is not pointing it
D. Like before, a composition should be added to the clip
E. Is this intended or mistake? IMHO, the lower right corner highlighting looks better if it's color is RED. It will be consistent with other highlighting.

SOFTWARE/OS VERSIONS
Windows: 7
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION