Loop to loop is bad - Try attaching your leader to the fly line
Fly Line To Leader Connections
Line to Leader Connection Preference and Why?
Why is my new fly line like this? Is there something wrong with my loop-to-loop connection? : r/flyfishing
How to Tie a Fly Line to a Leader (with Pictures) - wikiHow
Nail Knot Tutorial - Attach your leader to your fly line with this
FISHING KNOTS - Fly Line to Backing Knot
The ultimate leader to fly line connection for small stream fly
A Beginner's Guide to Building Leaders for Saltwater Fly Fishing