Appears that Amanita is a category twice - once labeled “Amanita mushrooms” https://www.inaturalist.org/taxa/48419?locale=en-US (the older genus category containing most observations) and once just Amanita https://www.inaturalist.org/taxa/954920?locale=en-US (appears recent).
It’s not a duplicate or a bug. Someone has been organizing the members of the genus Amanita into lower levels of taxonomy, in this case sections. One of those sections, as is common in cases like this shares the same name, thus you have Amanita the genus, and Amanita the section under Amanita the genus.
Once I got the hang of it, the section aspect has been very handy! Related https://forum.inaturalist.org/t/fungus-section-does-not-populate-identify-choices/7138?u=lotteryd
Amanita and Mycena both need this, I am glad to see that someone has been working on this.