I run two instances of Radarr to keep 4k movies in their own instance. I run the 4k instance on port 7979. It works well except that the WebUI link on the main docker page sends me to the 7878 server. I've updated the WebUI setting in the docker advanced settings to http://[IP]:[PORT:7979]/ but this docker ignores it. I tested changing this setting on some of my other dockers and it works. Running 6.5.3.