Using CCR as dude agent (not server) is impossible with latest firmware versions; with 6.46 it's even worse.
Selecting the CCR as Agent for the HeX, HAP-AC2 and RB951 causes all monitored devices behind the CCR to toggle between on- and offline all the time. The Connection between the devices is absolutely stable.
In the Dude I can see "Agent disconnected", successfully connected and after a few seconds disconnected again.
As a workaround I set up routing between CHR and all the other routers and selected the dude server as the agent. It's stable now, but not a final solution.
I can have winbox open to any of these devices all day long, without any disconnects. Agent also seems to use winbox for information gathering. (Wiki The_Dude_v6/Agents isn't too helpful how this works in detail)
Any idea what else I can try?