Lost - trying to wire 3 way smart switch

Any help would be much appreciated. I’m trying to wire a 3 way smart switch and I’ve never seen this configuration. I am using a Leviton DW6HD and a Leviton DD00R-DL. In the pictures below wiring box 1 has the hot identified by the red arrow. It has 3 jacketed wire bundles, two of which are standard black/white/ground but the third has black/white/red/ plus a forth black and red wire (plus ground)

In wiring box 2 the traveler bundle is the only bundle present with black/white/red/black-red + ground.

Anyone know how I need to wire this?

You need to map the circuit so you know exactly what each wire is doing, but it’s possible that the fourth wire is a traveler wire.

Also, it would help if you would post a picture showing the back of the existing dumb switch with the wires attached. :sunglasses:

Thanks for the response. I hate to sound dumb, but can you give me any insight into how to map the wires?

Unfortunately I removed the dumb switch right before I thought to take a picture. I do have this picture taken right after removal. It shows the black traveler and the mystery red/black pig tailed together.