It just doesn't happen. Further, if a question and information is vague, people may not bother. If you request replies be e-mailed, people may not bother as this is a newsgroup for shared discussion. If you only use your email handle rather than also furnishing your name, people maybe reluctant to respond. Everyone will see your message as MBMM and MEM are not high volume newsgroups.
Most individuals download every article automatically rather than just the headers.
Just give it time. You could change providers or add a second provider. You can complain to your service provider and hope a new news feed is implemented or that the service provider adds additional news feeds. Most will allow you to read but not post. If you choose this alternative, thus not being able to post directly to the newsgroup, you can use the option of e-mailing your articles directly to the moderator.