I'm a mod here and want to explain to you three things about how this place works. It's in HN's interest (and yours!) for your articles to be on this site, but you'll need to go about it differently in order for this to work.

* You guys are getting flagged by HN users. That's no doubt because of promotional voting and commenting (such as here: https://news.ycombinator.com/item?id=27508744), which is against the site rules [1]. It's obvious to experienced users that such votes and comments do not come organically from the community. The HN community is vigilant and considers these behaviors abusive. Your site has great articles for HN and is obviously not spam, but these things are what spammers do, so you're imprinting yourself in the community as spammers. This is not in your interest!

* You're also running afoul of this rule from [1]: "Please don't use HN primarily for promotion. It's ok to post your own stuff occasionally, but the primary use of the site should be for curiosity." On HN, the idea is for people to submit stories that they ran across and personally found intellectually interesting, not because they have something to promote. It's fine to post your own work, as long as it's interspersed with interesting posts from unrelated sources. When an account only submits promotionally, it feels like they're not participating as a community member, and HN users notice this and complain. Certainly when it's an entire ring of accounts the reaction is considerably worse!

I don't want to discourage you from submitting your own work, but it's best to build up a track record of interesting submissions from unrelated sources, and to intersperse your own articles with those. If you dig up interesting things from a variety of places, things people haven't run into before, then you'll be perceived as a community contributor rather than someone trying to market something. Particularly good are stories on out-of-the-way topics that rarely or never get attention. The best submissions are the ones that can't be predicted from any existing sequence [2]. Since your publication is producing articles on uncorrelated topics already, I imagine your interests must range in obscure places, so you could probably submit quite a few unexpected things if you choose to.

* Last point: an in-depth article about Roman currency is a great HN submission in principle, but it's too soon after the last major thread (https://news.ycombinator.com/item?id=27721748). Frontpage space is the scarcest resource this site has [3], and readers here have allergies to the same site or theme showing up too often. Since curiosity withers under repetition [4], submissions that in principle have curiosity-gratifying value start to feel tedious when they come in an observable pattern. You definitely can't have major threads on HN every couple of days. Every couple of months would work! Maybe once a month. Much more than that will provoke an immune response from readers here, and you definitely don't want to train them to habitually flag your site.

[1] https://news.ycombinator.com/newsguidelines.html and https://news.ycombinator.com/newsfaq.html

[2] https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...

[3] https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...

[4] https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...