The line I'm referring to is the one you can grab on an audio track in the Edit page to bring the levels up and down and to drop keyframes onto. It's so fine, faint, thin and hard to see. And since your playhead doesn't snap to it, it's like clicking and guessing to grab / edit it.
Mac Studio M1 Ultra 20C CPU | 64C GPU | 64GB RAM | 1TB SSD LG 42" OLED C2