This is perfectly internally consistent.
Nazis can be accepted while fighting a bigger enemy without having to accept them when the enemy is defeated.
But I think Schlock Mercenary has a better take on this: "The enemy of my enemy is my enemy's enemy. No more; no less."
"Nazis who travel to Ukraine to fight Russians are less bad people doing morally and ethically ambiguous things. Once they leave Ukraine, the actions they performed involving Russians are both unethical (because they willingly travelled there to murder conscripted teenagers) and ethical (because they willingly travelled there, presumably to defend the sovereignty of a nation they have tenuous cultural links with)"
Just wait 'til the Ukrainian Foreign Legion starts to be accused of things like massacres (whether legitimate or false reports for propaganda), then guys who were marching in BLM counter protests who went to Ukraine (again, running with the bad nazis doing good things) will have their social media histories paraded about to defame the entire foreign legion.
I wouldn't be comfortable working with a Nazi on a line in a kitchen, just as I'm sure they'd say the same about me, but if Russia invaded here, I'd be quite comfortable "walking with him to the end of the bridge," as the other poster said. Deal with the day-to-day bologna after you've dealt with the once-in-a-century bologna.
It's just... They wanted to control who was permitted to express nationalist sentiment, who were acceptable targets of "hate", and who was allowed to own guns.