I've had a similar story happen in the past. I was living in Japan looking for remote jobs and came across Couchbase. Interviewed well with the team who all seemed excited to get someone with my experience on board, however, the hiring manager said he wasn't sure he wanted to manage someone in my timezone. He pulled me into a separate call at the end of the rounds and asked some weird questions, which in hindsight we…
Never put in notice until background checks and all on boarding paperwork is 100% complete. Putting in notice on an offer letter is premature and, unfortunately, leads to bad results.
This seems like a normal societies way to secure the transition between jobs. I’m thankful I don’t live in any of these crazy places that make changing jobs seem like a severe stress way beyond what it should be.