I just noticed something interesting. I copied and renamed the route where I still have problems deleting waypoints. With the copied route, deleting the waypoints works without any problems, with the original route the problem still exists.
It is possible to insert a waypoint on iOS or Android but it is a bit “Hit and Miss”.
You need to zoom in to the full extent of the black route line.
I find that zooming back in every time you want to insert a waypoint even if the screen is fully zoomed in will help.
Sometimes a purposefull double click on the route line will also work and automatically add the waypoint or give you a prompt to confirm if you have that setting on.
Sometimes a long purposeful press on the route line will bring a pop up of the Icon and some other info, click the map, not the pop up, and when the pop up disappears the Insert icon will be there for you to click on the route line.
v1.6.9 brings back search on Android 9. I hope it can actually route me somewhere now, since I tried to use it last weekend to run a pre-made route, and it failed before the first waypoint, and then I tried to let it route me home and it just kept crashing.
In defence of MRA; there are so many different operation systems, flavors of operating systems and settings on individual devices, that it is very difficult to have an app that works under all cicrumstances.
Of course, this doesn't help you much, let's hope that the next iteration is more stable.
@Christian-Schrenk “The more waypoints are set, the more accurately the route is transmitted.“ Local conditions like heavy traffic or road closures can affect your TT and maybe cause it to take a diversion. Placing more waypoints does not make the route more accurate. In fact, it multiplies the chances of an inaccurate route if all waypoints are not fully checked as previously mentioned. And as you said, it makes rejoining your original route difficult.
And the language used on the maps is out of the control of MRA like @Hans-van-de-Ven-RouteXpert said in a previous reply, but I think we have found you a solution. 👍🏼