I’ll look up that switch 3g thanks. I think the last time I visited the hose issue it wasn’t mentioned. since you mention the screw I think it’s in too far however it’s set according to handle squeeze and if I back it out I have no lever. I have to wonder if anything was blocked wouldn’t it do it every time not randomly?
That's a big statement.
Do you notice any difference if the brake gets hot, say a couple strong applications in a row?
There are two ports in a master cylinder the main port it's fairly big say 1/8" and the equalization port, it's tiny, not much bigger than a single strand from a copper MC motorcycle wire. Setting your screw "in" quite a ways tends to block that port. You might be right on the edge of blocked or not.
I don't have a hard answer for you about what's going on but as others have mentioned air trapped in the line up at the MC banjo bolt or inside the caliper are favorite hiding places for some air. One thing I like to do is place the bike on the side stand, turn bars full stop left, the idea isgetting the MC higher than that MC banjo bolt. Back off that handle bolt, open the cap, squeeze release watch for bubbles repeat til they quit. See what you have.
There's other bleeding "tricks" too.
One is to remove the caliper, place it so the brake lines run ONLY up hill from caliper to MC, (NO low spots or dips) force BOTH caliper pistons back all the way. You may need to remove brake fluid form the reservoir so it doesn't over flow while doing this pump them back out with the lever added fluid if needed, maybe repeat then see what you have.
