### Implicit_plot with degenerate conics

I'm plotting some (possibly degenerate) conics via implicit_plot.

```
y = var('y')
implicit_plot((y*sqrt(sqrt(2) + 2) - x*sqrt(-sqrt(2) + 2))^2 == 0, (x,-2,2),(y,-2,2))
```

yields a blank plot for me. Yet this should be equivalent to

```
implicit_plot((y*sqrt(sqrt(2) + 2) - x*sqrt(-sqrt(2) + 2)) == 0, (x,-2,2),(y,-2,2))
```

which yields a line, as it should. On the other hand,

```
implicit_plot(x^2 == 0, (x,-2,2),(y,-2,2))
```

does give a vertical line. Why is this different? Is this a bug?

I'm running this on the cloud, using a free account on cocalc.com. Perhaps this has something to do with the problem?