It is part of AfD's standard platform that LGBTQ people receive fewer rights than straight people,

They've supported civil unions but not gay marriage, but consider it a settled issue. Their leader, Alice Weidel, is a lesbian woman with a Sri Lankan partner.

and that all foreigners should be rounded up and deported

The AfD has many immigrant supporters and members. That secret meeting they supposedly had, about "deporting immigrants who refuse to assimilate"? It was a random far-right crank meeting in which a single AfD member attended, and was alienated from his party for doing so. This is what Alice Weidel had to say about it, translated:

Untrue allegations of the most outrageous media and political scandals, ladies and gentlemen. These are DDR methods. I think it's great that they're now writing everything down in detail. Private encounter between personalities with different backgrounds, including one AfD member and people without party reservations. It wasn't a secret meeting either, just a private gathering that these corrective activists used secret service methods to construct a conspiracy theory from.

The Bundestag faction on how to deal with the millions of irregular and illegal migration since 2015 is not set in alleged secret meetings, but in party conference committees. It is based on the basic program of 2016 in the EU election program and the numerous statements and parliamentary speeches you can read and listen to. All right state resources to prevent illegal border crossings through more effective border controls. To revoke citizenships obtained illegally from criminals who are not entitled to naturalization. To expel and deport migrants who are criminals and terrorist suspects who do not have a right to stay.

Whoever is a German citizen belongs without question, without a doubt, to the German people. This is precisely why German citizenship must not be lost and distributed with a watering can. And that, ladies and gentlemen, is the enforcement of applicable law and regulations that have been neglected by the government for almost a decade in this process.

I certainly don't agree with them, but their platform is basically American Republican "tough on border and illegal immigrants" and "limiting and prioritizing skills based immigration" style.

This kind of disinformation is exactly how 2016 happened in the US. Trump says he wants to build a wall and curb illegal immigration, liberals say he wants to kick every Latino out of the country, his supporters get to shout "fake news" at everything. Calling them Nazis only feeds their supporters' victim complex; it's like Hillary's "basket of deplorables" but 100x worse, and AfD politicians get to go "you're upstanding citizens, but the woke left see you as evil for caring about your country. They're the real Nazis."

There are extremist minority politicians of the AfD who like to dogwhistle of course, which is also functionally the same as the GOP. Except if an AfD politician ever said something like "immigrants poison the blood of our country" as Trump did, they would be arrested.