Automatic placement/seamless dropping in of clips

Hi all

I';m sure I used to have the ability in fcpx for clips to drop in automatically after a previous clip. Right now i have to drag each clip in my timeline to be one after another - a very tedious, manual, long process

Can anyone be a lifesaver and advise what i NEED to change please?

in my example below you can see the tiniest gap after the red line/cursor thing. i just want a clip to be seamlessly fall in one after another

screenshot attached! thanks so much