How often have you seen sellers and their agents just ignore offers? It's four days for a response back unheard of? So unfortunately this happens really.
A good listing agent should be responsive to offers no matter what the offer is like. They should be able to give you a response back when you submit an offer, there's going to be an expiration on the offer that basically says, we expect to hear back from you within a certain timeframe.
Normally it's only a couple of days and then a seller should be able to get back to you with either a counter or rejection or approval. They should be able to give you an answer. So if you're not hearing back within four days, most likely your expiration is passed on that offer anyway, and it sounds like the seller just isn't replying or the listing agent isn't replying to you.
Might be worth having your agent reach out for a phone call and seeing what's going on. Really it just is frustrating when you're trying to negotiate with a seller and they don't wanna negotiate, right? they listed their home for sale. You're putting in an offer. Why aren't they responding? So what I would do is I would just reach out and see what you can do to talk with that listing agent to see how you can get things moving forward or if there's a counter that the seller wants to propose.
Ideally, it shouldn't just be radio silence, because that's not how negotiations work. At least that's not how good negotiations work. Talk to your realtor, and have them reach out to the listing agent. See what's going on and see if you can get a counter offer on that contract.