You have a Workflow Rule to send Surveys but the Survey language is not respected.
SAP Cloud for Customer
The Survey language is always based on the Browser Settings. The language set on the Browser, will be the language the Survey will be opened with, as long as the Survey is maintained on those languages.
This is the expected system behavior.
WKF ; Email ; Conditions ; Survey Matrix ; English ; Chinese ; German ; French ; Portuguese
KBA , LOD-LE-SUR , Survey , How To
SAP Cloud for Customer core applications all versions