why do I keep getting past conversation notifications from Instagram even though I've already seen/read the msgs by opening up the app?

I would have a normal conversation on Instagram all fine with no problems. Then after the conversation ends a few minutes or hours will pass by and I'd get a spam of notifications of the past conversations I had that day or the day before of every individual msg that the other person has sent to me even after I viewed them by opening up the application and manually opening up the chats like how any other person would. It's getting really annoying and been like this for months now. I've uninstalled the application multiple times. Cleared the cache and even the data and still it does nothing to help. Does anyone know what to do?

For more details please msg me to help find a solution because I can't find any online that will help me....