Here’s the deal.
If someone calls you a nazi sympathizer, they’re not saying you’re a nazi. They’re literally saying you sympathize with nazis, that you have sympathy for them.
Nazi sympathy can manifest in various ways.
If you think nazis should have an uncontested freedom to speak in the public sphere, you’re offering them sympathy.
If you think that their violence is just as bad as violence from the left, you’re offering them sympathy.
If you are quick to call out the left for their apparent hate and violence but have yet to call out the violence and hate of nazis, you’re offering them sympathy.
Any time you try to in any way minimize the seriousness of the radical messages of racism, nationalism, bigotry, and xenophobia of the nazis, you’re offering them sympathy.
If someone calls you a nazi sympathizer, listen. Understand what it is you’re saying that tells people you’re not fully condemning nazis.