You could try this ;
From the Title Browser T select, say, Lower Third . Drag this and place between your two clips A and B. Select your background as Black. Now delete the Text that you see . It is now just black, ie no text.
Now place a Cross Dissolve between clip A and the black text box.
You now have clip A then cross dissolve then black text box and then clip B.
You will need to play around with the timings but try cross dissolve at 0.21 and the black text box at 0.22
You may want to de-select 'Applies to all transitions" so as to not affect other transitions you have set up
This is not ideal and no doubt there is a better way of doing this, but it was all I could think of at this time.