Is there a bug with dynamically changing svgs?

I have an array of numbers (assume 1 - 5) that is mapped to svgs for display. When the user clicks on a number, the svg changes . However, the wrong svg is often updated (so, clicking on 3 will update the svg for 5 instead of 3).

I suspect this is a mithril svg update problem. Here's why:

1. Using the debugger and console.log show the code is behaving as expected.
2. I have an option to display some html markup instead of the svgs, and that works as expected.
3. The bug only appears after interaction/update--the initial display of the svg array is always correct.

I've tried hacking the key for the containing div, but that appears to make no difference.

Is this a known problem? Is there a work around?

I am using the current versions of Chrome and Edge.