Having used PM for a few 100km the last days (which showed 100% occurate navigation with easy usage and low power consumption, thanks to rinigus!), I maybe encountered a little bug both in 1.18 (half of the track) as in 1.19 (the other one after updating ) using OSMSS's maps.:

When having planned a route, PM shows a navigation icon in the right top corner of the map screen instead of in the left upper corner (see orange marks on screenshots, did not try in portrait mode).

As I was in a hurry both times, I did some screenshots, but didn't analyze the circumstances in which this happened. The only hint I can give is, that it happened between start of routing and driving...

Maybe it helps anyway...