in latest Locus
- tap on "add new route"
- tap on cancel: right most entry on bottom labeled "X"
- tap on any track currently displayed
After this time the name of the track ist displayed and right of this the "+" symbol. This means normally: add this point to a new track.
- tap on the "+" symbol
Observed on latest LineageOS with the following devices: Samsung P600, Galaxy S5 (g900f), Galaxy S3 (i9300)