Choppy slow motion

I am using iphone 12 pro max .. from past some time i am facing issue regarding slow motion.. whenever I record in slomo it always turn out choppy .. i have Iphone 8 plus also which works fine .. but 12 pro max isn’t smooth in slomos… it also drops frame rate.. you can see in the screenshot.. I recorded a clip in 240 fps but here its showing diff fps .. i updated my phone hoping it will solve my issue but it didn’t..