losing replies in a thread

I'm using hotmail and have begun to have problems in not seeing responses to group emails sent out. I see the original message and can reply, but when others reply to that same message, I don't see any of those replies.

This has happened several times ; I know I'm missing things because I have a linked gmail account and can see the rest of the replies in my gmail account but not my hotmail account.

I'm currently using my hotmail account for business but if I can't see group messages and responses, it's not functional.

How do I fix this?

Thanks!