@David-Potter-1 Hi David, we have encountered the road closure problem which is a Garmin problem, not MRA. However, I use a Zumo 346 and it would seem that if there is a road closure anywhere on your route, it auto recalculates whether you want it to or not (regardless of what your traffic settings are). Then there is an option to revert, which doesn't quite put it back to the plan as the unit makes its own decisions but then it auto recalculates again. It doesn't seem to matter where the closure is, it just totally explodes your route and not even logically.
Maybe someone reading this could shed some light as Garmin Support cannot without an update.