Having trouble with GE Smartthings switch

I have a multiple gang box that has a single power incoming with black, white and ground wires. From the box there are two sets of spots wired up on a single incoming wire. The white is common between the two sets it seems, while the black goes to one of them, and the red to another. There is also a ground wire coming from these. I have all LED spots and one set has 3 spots on it, the other set a single spot.

If I wire them into the GE smart switch, I put white to neutral and the common white of the lights. I put the line black to line, and either red or black to the outgoing lights. The spots turn on, but they never shut off completely. I’ve heard of that happening with the dimmers that don’t require a neutral wire, but not with these dimmers. It happens with either set of spots, haven’t tried wiring both yet.

Any ideas why the spots won’t turn off completely?

Leakage current, Some switches require a minimum load. Try wiring both. What switch?

How about leaving everything connected to the GE smart switch and disconnect the load wire (black or red) from the GE smart switch terminal and see if the light completely shut off. If not then wiring issue. If shuffle off then does the GE switch have load sensing?
Usually the min load requirement is for dimmer but it doesn’t hurt to double check. Best yet put in an incandescent bulb to test.