trevHCS:
It is very easy to have it selected in wring mode if you’ve tweaked it. When you get to final screen it should show sizes, weight limits etc and say “truck” in top right.Not had mine head for low bridges, but theres no central database of them so there will unknown ones esp on minor roads. Do you know where it was? Personally i set the height slightly higher than reality.
As for unsuitable roads - all it sees is a road as theres no info about widths etc available to the map makers, so on occasions they’ll try to send you down undoable ones. Ultimately its upto you to decide what’s suitable.
Whats wring mode ?