Not really an automatic way…
Use another video track with a transparent or color clip, set that clip for 2 seconds.
Make sure Snapping is enabled, and your timeline shows it is activated.
I believe @MusicalBox had shown this method in the past, if not someone else has.
The only way I see is to use the Slideshow feature.
First, all your clips need to be in the Playlist, in the right order.
Then you select all the clips
Then "Add selected to Slideshow
Set the parameters (clips length, transition duration and transition type) of the slideshow and click OK.
All your transitions will be the same length and will be the same type.
I did not have any problems when I made the transition settings and copied and pasted. I did not export. but when i play it, no problem appeared for me.
Judging by the thumbnails in your project, it looks like you repeat the same clip 4 times.
Did you try your method using completely different clips too?
The way you are doing it copies the original transition made with clips 1 and 2, and copies that original transition across your timeline. Copying a transition is not a creation of a transition of other clips. In your example, it shows you are also adding time to your total project. In creating a transition, like when you overlap two clips, on one track, it actually decreases the total time of a project.
In my example, I only applied a green color to the 1st clip.
The only way to do this today is to use the Slideshow generator. In the next version, you can use a custom transition wipe in the slideshow generator if you copy it to a special folder (more info will be in release notes).