Gratuity Payment - break in service from the India branch - Change of country

I worked with an investment banking firm for 7 years (2011-2018). In 4th year (2014) I moved to work in their UK branch, under UK payroll (XYZ Co. UK Ltd.), and then moved back to India branch in 2016. In 2018 I left this firm. Am I entitled to Gratuity as overall I've worked with this firm for 7 years. HR turned down the request for gratuity stating there is a break in service from the India branch between 2014 to 2016 (it should be continous service under India branch). Please clarify.

Dear Friend,
Unless what arrangement or agreement was there between you and your Bank during 2016 & 2018, is not told to this Forum, you may not get any right answer to your query.
Was there termination of your services in 2016? Was there fresh appointment of you in 2018? What service conditions you were subjected in abroad and which country? Is that country has SSA with India?

Ohh..
You did mention the name of country UK.
There is no SSA between India & UK.