UK resident working overseas. Planning a 2 week vacation. For purposes of travel insurance, how long is my "trip"? [closed]

Yes you almost certainly need another policy.

First the insurance makes it clear that your trip has to start and end in the UK, which, if you are talking about your vacation, it doesn't. That's absolutely normal in travel insurance. If you wanted to have the insurer consider this "one big 400 day+ trip" you would have to buy insurance for the whole 400+ days (which would fall under a completely different category from vacation travel insurance).

Second, you are probably not a UK resident. You are not a UK resident (for tax purposes) if you work full time overseas and spend less than 91 days in the UK during the year. If you aren't paying taxes to the UK then you are almost certainly not a UK resident.

If you are thinking about health coverage, your first step should be to look at whatever health coverage you already have to cover your time in China. You might find it already covers trips abroad. If not you are definitely going to need either a policy based in China or a worldwide policy that doesn't assume UK residence.