And this is why standard practice now should be to have all devices turned completely off with all FaceID/ fingerprint unlocking features turned off before you enter any US customs hall. They cannot compel you to tell them your password, but they can use faceID to open your phone.
Also, after being detained, you only know one word and that word is “lawyer.”
Yup. They can detain you, take your phone, and just break into it. At best you leave without your electronics. At worst you don't get to leave. At extra worst, you leave to El Salvador.
See, for example, this case from Louisiana where the defendant said, "Why don't you just give me a lawyer, dawg," and the state Supreme Court found this to be an ambiguous request as there is no such thing as a "lawyer dog."