Obsidian isn't European, but Canadian. Also it's "local first" so all your files are on your machine. There's a sync functionality that you can buy, or you can sync it yourself.
I'd give it a go. Plenty of plugins that can do pretty much whatever you want, including kanban boards, project management tasks, etc.
So if we can just get Canada into the EU it'll be a European product. ;)
There is taiga.io located in Spain and open source. I'm not sure if there's an official mobile app, but there are at least one unofficial one (the mobile version of the webapp is very well done otherwise). I've been using it for a collaborative project and I like it more than Trello.