I've used a lot of Redmine, Phabricator and Jira. Redmine feels really old and dealing with upgrades that will necessarily break one of the plugin needed to make it decent is painful. If you don't touch it, it works just fine though. Phabricator is really cool, requires some good tech knowledge to administrate, biggest pain point was the ci cd apps that were more complex than the rest. Jira is what I'm currently using, works great for all but your Jira admin will decide of your happiness, a bad setup with bad workflow will kill productivity.