I don't want to make them feel I'm dismissing their whole political stand, I've taken feminist postures many times myself because I take the side of justice.

But now I feel used because it seems some of them only listen to me when I'm actively helping their cause under their terms, but if I offer this type of insight they shut me out.

I care because my community is in fact troubled with double standards affecting both women and men. I've found many hateful speech and attitudes being fed. I'm not a fan of judging people, only ideas. Some ideas stand in the way for them to be listened to.

I don't believe there are "misogynists" and "misandrists", but people acting on misogynistic and misandristic ideas I have no trouble debating this topic with men shooting themselves on the foot with misandristic comments coming from the "macho" spectrum, like:

Yeah dude, we men are spendable, nature says so, wars prove me right.

But I don't know how to discuss with a feminist group saying things like:

"Of course men are allowed to cry, but to be honest it kinda does make them less manly"

Or

"That will be done by robots soon and we won't need men."

Or

What is he good for if he can't (insert stereotypical manly skill)

I've found it very difficult to bring up the topic. In the past I did approach a couple of groups with this issue. Their answers were similar to:

"Misandrism? What is that, does that even exist?"

And:

"That's an anti-feminist made-up word"

Which is the same as being dismissed.

I tried to explain what I knew about it and made the observation that it applies to both men and women.

While trying to remain cordial and constructive during these discussions, there are individuals with a tendency to throw popular terms at me like "mansplaining".

Answering

"Telling you a word exists because the phenomenon exists is not mansplaining"

didn't help. Defending my views become harder when you realize the word is not even included in most dictionaries (including apple's, windows, chrome's auto-correct tools).

The group I'd be approaching now has direct influence on a person I care about deeply, my girlfriend. They gather at the place I share with her usually after they have larger meetings. But I've also noticed those comments at larger meetings/gatherings (weddings, congresses, etc), not only my distant family but also friend's events and at other events where many women gather and men are minority.

How can I approach an otherwise open-minded feminist group that seems biased against hearing about misandry?

Objective:
Remaining amicably, for them not to feel rejection on a personal way neither on a philosophical way, so they can still gather at our home and discuss feminism and activism, keeping hateful ideas out.

Phrasing confrontational arguments in a polite sounding sentence would not nearly suffice, that's why I selected the conflict-aversion tag. I'm expecting a smart strategy that includes a way to measure success.