I have a 3-way config with two toggle switches (vs. the "paddle/decora" style). Light is in the middle of the switches. The switch I'm replacing with the Lutron is at the end of the run. Wired thusly: https://3wayswitchwiring.com/iotty-3-way-switch-wiring
(the first one they show as "lotty")

Power goes into the first switch with 14/2. 14/3 is then run from that switch to the light fixture. And another 14/3 is then run from there to the end switch.
I've labeled the wires appropriately (I did the install so I know what was run from where to where and I printed labels for each set of wires).

NO Neutral (they are all wired together, except for the one that's coded as "hot/traveler" in the fixture.
Ground continuity is good (everything is verified grounded).

Lutrons wiring instructions are kinda bad (IMO), although the Black and Decker terminology varies with Lutrons and others (Common, Hot, Traveler and lutron just goes by colors and "travelers"). Of course, in a 3-way the common isn't the same color always depending on which switch you're looking at.

Anyway, I have triple-checked the wiring and even took a picture of the old 3-way switch wiring before I removed it and replaced it with the Lutron.

I've reversed/switched the traveler wire on the Lutron to no avail.

The issue is the minute power is restored, the light stays on no matter what (neither switch will turn it off).

From what I've gathered this can only be caused by an open/bad ground (which multimeter/ohmeter reveals is NOT the case), or mis-wired (which I say is not the case), or possibly bad Lutron switch.

Although I did see something on the Lutron site that indicated some older mechanical switches can have a digital circuit or something? These are Leviton 3-way switches purchased around 2006 or so.

I have jumpered the first switch as indicated with the little yellow jumper. Although I see two diff. Lutron diagrams. One has you wire nut the 2 blacks to one end of the yellow wire and then connect the other end of the yellow to the Common screw on the switch. The other one has you leave both black wires (one on the common, the other on one of the travelers) and then ADD the yellow wire (one end to each). I'm using the one that came with the instruction manual where you wire nut them all together and then connect the one yellow end to the Common screw.

I have no idea why it's doing this, so obviously I'm missing something.

I have tried a 2nd Lutron occupancy sensor (same model) as well, same results.