Yeah, I would class this under problems caused by partner(s) being jerks, which is not limited to poly by any stretch. They need to either shape up and treat you with the respect and warmth you deserve, or at least explain what the heck the deal is. Maybe instead of regularly bringing it up, like you have been and which can just become nagging, you could just wait until they have the time and mental energy to see you and then have a bigger, serious conversation with them about it. If they won't make the time for that, or won't listen and respond in a caring way, they're not worth it.
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.