I bought a motion sensing porch light with stranded wires coming out.

When I tried to connect it to the solid wire with twist on connectors (2
solid wires + 1 stranded), one stranded wire slipped out after a slight tug.
The stranded wires is of a smaller guage.

I thought about making the leads on the stranded wire longer and wrap it
around the two solid wires first. But the strands being so thin, might be
cut by twisiting the connector on it.

In the end, I removed the porch light, twisted each stranded wire all by
itself, and put solder on it. This essentially turned the strands into a
solid wire. Then I twisted it on with the solid wires.

Is this the correct solution?