Hi dalsenoa,
Thank you very much for reaching out. We’ve implemented the suggested Bulk Import/Export feature, it’s however a premium feature so only users who have a key see this.
Now regarding the your use case to import new articles, we have a security in the plugin to check if an article has already been imported to avoid duplicated content, so if you have deleted the old articles, please make sure they are really fully deleted from your system and not just in the trash (still in your database) , then when re-importing the feeds again , select “save and Import” instead of just “save” and make sure to have the appropriate number of items you’d like to import high. I suspect, your articles are still in your trash or you have a backup plugin storing those articles in the database but not showing them on the admin section, that’s where I’ll start investigating.
Hope this could help .
Cheers,
The RSS Post Importer
https://www.rsspostimporter.com