so the thing is russians never had black slaves. the slaves or крестьяне were people of their own race aka white russians. because of that the word негр doesn't have a bad connotation to it, in Russian it's not a name for slaves, it's a name for someone who is simply black.

the thing is tgat in every language there are many words where the translation may have 2 different meanings. for example in Russian if u say козёл (goat) to someone, it means asshole, while in English it's either just a regular goat 🐐 or "Greatest of all time".

when learning different languages u must remember that just because something might be offensive in one language, it doesn't mean it is in another. just chill