Relating to baitcasting with 30# braid and 15-20# leaders.  I use an Alberto Knot and I'm pretty good at tying and trimming it.  Sometimes that little catch of the knot going through rod guides will cause a backlash.  A fresh leader will typically be the length of rod tip to reel, getting shorter with each re-tie;  I replace them when they reach about 3 feet, and it seems a backlash is more likely to occur with a short leader.  Do any of you experience this and do you have a cure?

Cure fg knot

You want to trim all of the tag to avoid blow by knots.  Nail clippers are the best I've found to get a flush trim without damaging anything else.  You can learn an FG and they're not hard to tie skill wise, but they take more time and concentration.  I can't tie an FG in the dark or in the surf and keep my eye on the waves at the same time, that's why my go to is an Alberto.

Leader is not a requirement for bass fishing.  I don't use them.  Problem cured.

^^^^this^^^^
Tom👍

With casting gear I use a leader for all baits with treble hooks to mitigate line wrap...... Devil's Horse being worse case scenario on front prop.

Use nothing but Alberto with no issues at all. 

20# braid to 12# flouro.

If it is catching on the tip top guide you could try changing to a larger size ring on that guide.

I use back to back nail knots, a fly tackle knot. Gives a reliable compact knot. I make the leader long enough so the knot goes into the reel and have no problems.

I don't use leaders with casting gear, only on spinning and use the FG knot to connect the braid to leader. JMHO

Having the leader tag pointing forward when casting may be what's causing issues. Try some different leader knots.

I get 40lb 832 to a 25lb sniper leader through #5 guides without issue using the simplified GT knot from a few years ago. It's not a small knot, but is easy to tie. It will occasionally catch when reeling in through the guides, but not when casting. 

Are you using microguides by any chance? I fish braid to leader almost exclusively and don't ever have this issue. Alberto and Blood knots for me. I will say, 30lb braid to 20lb leader is a large gap in line diameter and that can play a roll. I would either downsize the leader or upsize the braid to at least 40 if not 50lb. My typical setup is 30lb to 12lb or 40lb to 16/20lb. 

I only use microguides when using no leader.  From all the replies, general opinions are for smaller diameter line, larger eyelets, and/or learn the FG knot.  I'll try, but know I won't like it;  especially learning the FG knot.  Thankyou everyone.