What do you ask to get information?

It's admirable that you want your character to interact with all the NPCs, but remember that art imitates life.

How often do you walk up to some random person in real life and ask "How are you today?", only to be met with "Good." and the conversation is over?

For the most part, people are not used to a random person wanting to talk to them in any in-depth manner. You get these dismissive responses for exactly that reason. Over a lifetime, people learn that virtually no one really gives a shit how they're doing when they ask "How are you today?" and reply with the least amount of energy required.

And that's where your DM is coming from when they say you're not asking the "right" things. Essentially, your DM sees it as you asking everyone how they're doing, and all of those people have been trained over the course of their lifetimes to respond with the least amount of energy required.

Ask the NPC something they wouldn't be expecting, keep it on-topic with the story/campaign so you're not just wasting game session time chit-chatting with every NPC who looks your way about how beautiful a day it was today, if the NPC ever goes fishing, or other things which aren't important in the grand scheme of things and that neither you nor your character will remember 6 rounds from now...

/r/DnD Thread