Hi @alienandro
Welcome to the AntennaPod community. Indeed gpodder.net is overloaded and not actively maintained. See e.g. Problem with GPodder.net; Syncronisation via Gpodder doesn’t work; Gpodder down? and others.
AntennaPod version 2.5 (probably soon to release as beta on Google Play) will support synchronisation with gpodder-server-app-on-Nextcloud.