I have been uploading comic art images by Moebius for several weeks almost daily to the !eurographicnovels@lemm.ee community, where I´m a moderator myself. All those images have disappeared. Modlog says the images have been deleted by "admin". Modlog gives no reason for this but says the images were later restored by "admin" but that is not true. All my comic art posts have been destroyed and are empty posts now. I was not even contacted a single time about this and honestly can´t think of a reason because I had uploaded exclusively "safe for work" and apolitical material. We are trying to build a community for european graphic novels like "Tintin", "Lucky Luke" and "The Incal" and I put a lot of love in those posts because I want to help make our community interesting and grow. However - I have been stongly discouraged to contribute content now that I have seen it gets arbitrarily wiped by anonymus admins. How can I find out what happened, who deleted my stuff and why they did so? How can I avoid this happeing to my posts in the future?
Really? That seems weird. I feel like they should live with the post, not the author.
They do live with the post. When you post something to another instance's community, you're not posting there, you're posting to a copy of the community hosted by your home instance. The post is always made from the poster's instance's copy of the community, and it federates back.