IG DMs not being shown as "seen" even though they have been

I just recently bought a new phone and I downloaded IG. I sent a DM and I was checking to see if they had seen it but it didn't show anything at all. So, out of curiosity, I went to check other messages that I had sent to other people who had actually responded, but those messages didn't show as "seen" either, even as I was looking at the responses. I pressed the message and it gave me a few options including a list of reactions or to unsend but it nowhere did it say that it was received or seen. I went into the settings but there weren't any option there that would help. I also went to see if there was an update but I had just downloaded it, so i was up to all up to speed. Is there something that I'm missing? Any help would be greatly appreciated.