d3 v4 force graph doesn't stop moving after applying links - d3.js

Question

I have this code that is working great except that the only way I can figure out to stop making it spin is to turn up the velocityDecay, which makes the animation the point when a new node is introduced to be quite slow -- and doesn't actually stabilize the animation -- it's always moving slightly.
Here's the relevant parts of the code (or tell me if there are other important components):
```
60 let simulation = d3.forceSimulation()
61 .force('link', d3.forceLink()
62 .id((d) => { return d.index + 1 })
63 .distance(200)
64 .strength(1))
65 .force('charge', d3.forceManyBody())
66 .force('x', d3.forceX())
67 .force('y', d3.forceY())
68 .alphaTarget(1)
69 .on('tick', ticked)
70 .force('center', d3.forceCenter(window.innerWidth/2, window.innerHeight/2))
71 .force('collide', d3.forceCollide( (d) => { return 150 }).iterations(16))
72
73 svg.append('g').attr('class', 'links')
74
75 let link = svg.select('.links')
76 .selectAll('.link')
77 .data(links)
78 .enter().append('path')
79 .attr('class', 'link')
80 .attr('fill', 'transparent')
81 .attr('stroke', 'black')
82 .attr('stroke-width', '10px')
83 .exit()
84 .remove()
107 link = link.data(links)
108 .enter().append('path')
109 .attr('class', (d) => {
110 return 'link link-' + d.source + '-' + d.target
111 })
112 .attr('fill', 'transparent')
113 .attr('stroke', 'black')
114 .attr('stroke-width', '10px')
115 .merge(link)
116 link.exit().remove()
147 simulation.nodes(nodes)
148 .on('tick', ticked)
149 simulation
150 .force('charge', d3.forceManyBody())
151 // .force('center', d3.forceCenter(window.innerWidth/2, window.innerHeight/2))
152 // .force('collide', d3.forceCollide( (d) => { return 150 }).iterations(156))
153 // .alphaTarget(1)
154 .alphaDecay(.5)
155 // .alpha(1)
156 // .velocityDecay(.95)
157 .force('link', d3.forceLink()
158 .id((d) => { return d.index + 1})
159 .distance(200)
160 .iterations(20)
161 .strength(1))
162 .force('x', d3.forceX())
163 .force('y', d3.forceY())
164 .force('link').links(links)
165 simulation.restart()
```