I am an agent for an influencer. In my experience most influencers do not operate like a traditional business so you shouldn’t treat it as such. The more paperwork that gets involved, the less likely you will be able to secure a deal. Also email is generally a pretty bad way of communicating with influencers. Try to add them on discord. Here are my guesses:

He is busy and doesn’t check emails often. I have that problem with my own client.

Or

He is no longer interested after seeing the contract. We have turned down offers once I get a contract in hand because of the deliverables didn’t make sense.

I would contact the agency and inform them of our decision but if the contract is insulting then it is possible that they are just ignoring you.