I was using Podgrab, but it's basically not maintained at all. There's a whole set of podcasts that aren't accessible because the useragent string hasn't been updated and other issues that have gathered. I'd consider it a dead project, which sucks, it was simple and worked. There have been some forks, but I seem to remember issues with them as well and they also appear dead.

I used to use GPodder before that. Don't quite recall why I moved away (probably because it was more a desktop application than a service). Might have to give it a go again.

There's another recent project PodFetch that's been self-promoting in the issues sections of other projects, but it seemed young and not in a useable state when I tried it.

I too want to like Audiobookshelf but for my collection, it's been very unstable and unreliable.