For what it’s worth, rather than answering directly, here is a link to another post where I attempted to answer this question. I hope it helps. If not someone else will no doubt also jump in.
I don’t recall if you told us which pump you are using. If you are using one of the newer pumps which automatically change your basil settings and/or deliver correction boluses that could be another reason why you are having problems.
So, which pump are you using?