oh wow, you are correct, choosing session-> close all windows , does infact accomplish this (wo existing the app). thanks!wrongThe suggestion from another user session-> close all windows , only occurs when you EXIT winbox (ie the next time you connect all windows will be closed).
IMHO RouterOS should have native DynDns and NO-IP support. It's not allways possible to get rid of ISP device or use it as a bridge.
For simple DDNS requirements there is the built in DDNS under /ip cloud ? It's free and it works
It's url is serial_numer.sn.mynetname.net