for GetPlannedTripsByLatLon and GetPlannedTripsByStops :

if the starting leg is a walk then the beginning time of the walk always matches the beginning time of next leg of the bus service, ie the time btx the end time of the initial walk and the begin of the next bus is always negative.

if the final leg is a walk then the beginning time of the walk always matches the end time of the walk ie the final walk time is always 0 mins even for 0.5 miles.

so it uses two different assumed walking speeds namely the speed of light and another speed much faster than that! thus the recommended starting and end times will make you miss the first bus and not account for the final walking dist/time.

now that you fixed the above bug a new caveat was introduced.
for all the planned trips if the first leg is a walk then the recommended 5 min wait time is included in the itinerary and the total travel time.
this leads to inconsistent comparisons of itinerary times since one with an initial bus leg does not include this 5 min overhead that a walk one does and hence is given preference over them. it furthermore excludes any immediate trips if walking cant get you there a full 5 min ahead of the bus, but if the start leg is a bus it shows trips leaving immediately.
this 5 min wait time should be removed from the planning, the rider should be the one anticipating that, not the TD mandating it non-consistently.