Can They block my surveillance?
That cow is already out of the barn, because you told us the police officer BLOCKED your "spybell".
Nobody here is involved in crime, this doesn't seem right
You do NOT need to answer your door.
You do NOT need to sign for a certified letter.
You do NOT need to answer your telephone.
You have the RIGHT to remain silent.
You have the right to have an attorney represent your interests.
If the police arrive to serve a search warrant, you won't need to bother answering because they'll let themselves into your home.
This might not be a criminal matter.
The officer may have been trying to serve you with a summons to appear as a witness or defendant in a civil matter.
I suggest you seek the advice of a local attorney or two.
You might also wish to call a bail bondsman and ask if there are any warrants out for your arrest.
That call won't cost you anything but your time.
You should search local court records and even any federal records that involve you or yours:
...
https://www.pacer.gov/findcase.html ...
The police and/or inspector might be looking for a friend of yours or a relative.
Even if that is the case, you don't have to answer any questions.
Be careful when you drive your car(s), there's probably a "BOLO" out on them and you.