Tax treaty for resident alien

[shupeizh]

I was on J1 starting from Jan 2018 to June 2018 as an intern (not paid). Then I changed my visa status to H1B in July 2018 until Aug 2019, during which I was exempt from tax due to the US-China treaty for researchers. Now I changed my position in Aug 2019 and got H1B transfer, but I was told by payroll office that I'm not eligible for the treaty because I did not reestablish my residency. To my understanding, if I enter the us as non-resident alien, the treaty exemption will continue to apply (3y), and this is provided by the exception within the treaty that applies to all resident alien (stated in the treaty itself) . Anybody possible could help explain why?

[Anonymous]

what do you mean changed your position?   from what to what?