Incorrect SVG diagram

[sletz]

For this codeprocess = _~_;

[eleses]

I'm not sure if it's related, but I also get something weird on some diagrams.

import("stdfaust.lib");

sumstepA(K, x) = par (i, N, Sx(i, K)) with {
    N = outputs(x);
    Sx(j,j) = (x : ba.selector(j-1, N)) + (x : ba.selector(j, N));
    Sx(j,z) = x : ba.selector(j, N);
};

process = (1, 2.1) <: sumstepA(1, si.bus(2)); 

I'm not sure what's the meaning of that "merger" I circled in red. No sum takes place there.
I mean the output on the 2nd line is 3.1, not 4.1 as the diagram suggests.

I think the numerical output is correct (for the program), and the diagram is wrong.

Somewhat simpler repro of the same svg bug