Once a survey is started on the last published version, the respondent will continue to see the last published version on which it started the survey instead of the current published version. 

One of the way to get them current published version is send them a retake link once they conplete the survey OR do a fresh email distribution again. 

Having the participants clear their cookies/cache can help reflect edits if using an anonymous link.

@Su_Zin - If  you delete the partial responses, the respondents will start the newly published survey from the beginning.

Thank you everyone.