I used Gaussian Blur transition.
It looks good and works properly when viewing it in the preview window.
The default transition duration is 00.00.02.000.
Then I produce it,  in the final output video, the middle of the Gaussian Blur is blue !  WTF !
I tried shorter transition duration times and still damn blue color shows in the middle.
I have been messing around with this problem all day and it makes me angry how stupid this problem is !