I was not happy with the dimmers I put in with my kitchen LEDs due to flicker, so I swapped them back out today. Now I have a miswire somewhere. Any advice?

The problem is the line side wire needs to be "on" for the switch to work. If it's on, then the 2nd load side switch works on/off. If line side switch is off, then the load side does nothing. I'm assuming I have the wires on the load side swapped somehow.

Here's how (I think) I wired it:

All white wires are tied together.

Switch A: Line side, normal 3 way screw terminal
Line side black wire connected to common terminal on a normal 3 way switch.
Red and Black (traveller) wires connected to the copper terminals (didn't pay attention to which was which - is this important?)

Switch B: Load side, Lutron DVCL-235P
I think the load black wire is the one that is wired together with several black wires in the switch (there are 9 lights on this circuit)
Load black wire connected to black pigtail wire (I also tried the red pigtail)
Red and Black traveller wires connected to red and red/white pigtails on the switch (or black and red/white when I tried the red pigtail as load)

Do the traveller wires need to match up somehow? Do I need to swap them on switch B?
I'm not sure what else I did that was dumb and caused the problem, but I assume it's w/ switch B.

Can't find the instructions to the switch anywhere and the online instructions seem confusing on which one should be connected to the load.