"The Squad" didn't exist in 2016. Also, she wasn't "popular" per se with Cubans (many Miami Cubans hate the Clintons because of the Elián González fiasco) and Venezuelans, Trump won their vote in 2016. She just didn't do as bad as Biden.
Another reason is that Trump didn't make immigration a focus of his campaign this year. In 2016, he was all about "Build the wall!", "Ban Muslims!", "Deport illegals!", etc. Notice how this year - he rarely ever mentioned anything to do with immigration. His less harsh rhetoric against immigration (though, his administration's immigration policies is still very restrictive) made some Latinos more comfortable with voting for him this year.