I'm trying to get two instances of radarr up and going.  I've created a second docker using the first radarr as an image then I changed it's app-data to create a new folder called radarr2.  Now it has it's own app data folder.  I've been reading where to get this setup working I need to change the ports. I'm unsure which to change but can't seem to change anything.  If I go into host and change 7878 to 8787 radarr still starts with port 7878.  If when creating the new docker I change the container port from 7878 to 8787 (the one that looks grayed out but you can edit) and still change the host ports to 8787 nothing happens.  If I go into the config file I can't seem to change the ports and make it stick.  What am I doing wrong?  New to this but hoping I don't have to mess with it in the future. 

Your containers are working in host mode. TCP port mappings are ignored in host mode. You need to ensure they get different IP addresses, which currently isn't the case.

Ok..... so how? 

Set the network type to be "bridge" (which is the default for those templates)  Then you can adjust the host port to suit  (or network type to be Custom:BR0 and assign them separate IP addresses)  Choice is up to you

And, in bridge mode, there is very little reason to ever have to adjust the container port (as you've done) from 7878 to instead be 8787.  If you're going the bridge method, change the container port back to be 7878.  Only ever adjust the host port

I installed pi-alert and have it running.. IT however does not seem to discover anything.. Only finds itself... Is there something I am missing ?