@Reinhard-Punz I think the system is working pretty much as intended
Any avoidance setting set in the MRA web planner is set the same in the MRA app for that route,
the settings are part of the route & are synchronised in your account
When planning if you want to ignore road closures then "Disable Seasonal Closure" option should be enabled
this way you can plan the path you want to take regardless of what the road situation maybe today,
in 6 months or a year from now
The term "Seasonal" is a poor description of what the function does, originally it was for winter high mountain passes but its function has been expanded so now it also ignores temporary road closures
If in the navigation app you decide to be online allow traffic aware route calculations of course the app will recalculate the route with the current data it has available
As you have correctly discovered if you want to ride a route exactly as you have planned then you have to ride the path as a track & for complete peace of mind be in offline mode, that way nothing can interfere with your plan
If you want to ride as a route then your open to changes being made to the planned path
You cant blame the app for doing what you tell it to do
In your settings you may find it useful to enable the function "Navigation Settings > Screen Layout > Lines > Show Original Route"
This displays a white line of the original route/track on the background of the map so you can easily see where the directional path is deviating from the original planed path