As soon as an epic gets updated to Done by our automations (when all childs are done):

The epic isn't displaying anymore on the basic roadmap, although the settings of the roadmap view are as follows:

Any idea why that is? I've reviewed the filter used to fill the project board and the epic is still available in there.
Also we are nearing 3000 tickets but not there yet, as I read there may be such a limitation as well.