Michal
I wonder about my 'phone or Locus Map installation sometimes: I have experienced difficulties over time with several procedures that seem should be straightforward. This is another one: I do not obtain a reducing distance or time doing precisely what you wrote - I select the tack on the map then 'Navigation/Guidance'. I wondered if the track had to be a route as was the case with my previous Garmin eTrex, but it does not seem to be so here so far as I read in the manual.
I thank you again for confirming the action, anyway; I shall continue to persevere.