Hello @saphorin
Some options remain in the database by default, so you don’t lose settings if you switch off-on the plugin. This is pretty common with WP plugins in general.
But also pretty common is some kind of settings that will allow you to force-delete any data from the database upon uninstallation. You should be able to find these options in Hummingbird > Settings > Data & Settings. Ref: https://wpmudev.com/docs/wpmu-dev-plugins/hummingbird/#data-settings
These are also some options to clear DB from orphaned tables coming from the Asset Optimization module in Hummingbird > Advanced Tools > Plugin Health. Ref: https://wpmudev.com/docs/wpmu-dev-plugins/hummingbird/#plugin-health
Let us know if any of these options assist.
If not, could you please share some more details about which files or DB tables remained in your system so we can further advise?
Hopefully, we will be able to clarify/resolve this and you could review the 1-star rating here. ??
Take care,
Dimitris