Applicant and assignee are not the same thing. To change the applicant you will need to file a new ADS. See MPEP

325 Establishing Right of Assignee To Take Action in Application Filed On or After September 16, 2012 [R-10.2019]

An assignee who is not the original applicant must become the applicant under 37 CFR 1.46(a) in order to request or take action in a patent application. A request to change the applicant under 37 CFR 1.46(c)(2) must be filed and must be accompanied by an application data sheet under 37 CFR 1.76 specifying the applicant in the applicant information section and comply with 37 CFR 3.71 and 37 CFR 3.73.

Applicant and assignee are not the same thing. To change the applicant you will need to file a "request to take action" from the new assignee and a new ADS. See MPEP

325 Establishing Right of Assignee To Take Action in Application Filed On or After September 16, 2012 [R-10.2019]

An assignee who is not the original applicant must become the applicant under 37 CFR 1.46(a) in order to request or take action in a patent application. A request to change the applicant under 37 CFR 1.46(c)(2) must be filed and must be accompanied by an application data sheet under 37 CFR 1.76 specifying the applicant in the applicant information section and comply with 37 CFR 3.71 and 37 CFR 3.73.