You get a “stepped” routing if the routing deviates too far from the direct route: it ends up on the edge of the isochrone. To avoid this, increase the sweep angle in Settings > Routing > “Sweep angle” (Expert mode, reserved for Premium subscribers). The default is 220°. If your device is fast enough, set it to 360° and you’ll never have to wonder again.
If you haven’t taken the Premium option, add an intermediate target with “Add a target”. You can place it on the stepped routing, towards its middle.
With a sweep angle of 220°, you get steps:
With a 360° sweep angle, the steps have disappeared:
To go further: Expert mode and Routing.