Alternative to Azure DevOps Boards

Hi All! I'm looking for an alternative to Azure DevOps boards for my project management. I'm particularly interested in the ability to create relationships between tasks (parent/child and predecessor/successor especially) and to organize cards/stories into parent features or epics or however (I don't care what they're "called"). I've tried alternativeto.net but I'm just not finding what I'd hoped.

I'd prefer FOSS and self-hostable (especially YunoHost, for which I've tried Focal Board which comes close), but I wouldn't mind local-only or something online if they have a good privacy policy.

Any suggestions are totally welcome. Thanks in advance!