Doing business from the US is a minefield today, not at all like it used to be. Almost any other country is better if you just want to focus on running a business, so not so surprising that they relocated.
The previous US administration going to war with China on trade created a lot of uncertainty and concern surrounding tariffs and delays/parts availability.
Through that lens it probably makes a lot of sense to simply move your operation to China, when that covers the bulk of the relevant supply chain for your products. Especially if you have no other barriers deterring the relocation, like language or cultural challenges...
If they do business from China or Hong Kong they can get away with shoddy 1 month warranty, simple as that. Nobody's gonna bust those who are behind the company from countries like China, Hong Kong, Vietnam, ...
