Any Idea What's Going on Here?

So, I'm a content writer with 7+ YOE.

I applied for a role in a UK based company in Naukri. The ad was posted by a third party consultant. This consultant called me and asked all the necessary details.

After that, I had a virtual interview last Monday with the marketing manager. It lasted roughly 20 minutes. The questions were mostly about my experience and my approach. I asked the manager about the remaining rounds, he told me that I may have 1 or 2 rounds based on the feedback he shared.

The next day, the consultant calls me and tells me that they are happy with the interview and that I should expect a call from the HR soon.

The week ended and I got zero response from either parties. I assumed I was rejected but thought of giving one more shot. On Monday, I called the consultant and he told me that he'll ask the HR to talk me with me and release the offer.

Today, I recieved a call from a UK number. The person congratulated me for the new job and said he'll share the offer letter by tomorrow or Monday.

My gut tells me there's something going on. I have switched 4 times and this is the first time I'm being hired without asking for a written test. Plus, there was zero negotiation on the salary part.

Your thoughts on all this?

Thanks for reading.