The SameSite attribute is ignored when flask-mongoengine session interface is used. See save_session in flask-mongoengine and flask: https://github.com/MongoEngine/flask-mongoengine/blob/master/flask_mongoengine/sessions.py#L79 https://github.com/pallets/flask/blob/main/src/flask/sessions.py#L373
The SameSite attribute is ignored when flask-mongoengine session interface is used. See save_session in flask-mongoengine and flask:
https://github.com/MongoEngine/flask-mongoengine/blob/master/flask_mongoengine/sessions.py#L79
https://github.com/pallets/flask/blob/main/src/flask/sessions.py#L373