For Tipped Arrows that are of the "Awkward", "Thick", or "Mundane" potion type, their name only shows as "Tipped Arrow". However, they still behave as separate Tipped Arrows (you can't stack them together and their "Potion" tag is different). To reproduce this, craft a Tipped Arrow using an Awkward, Thick, or Mundane Lingering Potion. When you craft one of these arrows, the name will only show "Tipped Arrow".
This can also be reproduced by looking in the "Combat" category of the Creative menu and scrolling down to the section with the Tipped Arrows. The Awkward, Thick, and Mundane Tipped Arrows are listed here, but still use a generic name ("Tipped Arrow").
This could be fixed by changing the translation strings for these arrows.
"item.minecraft.tipped_arrow.effect.awkward": "Awkward Tipped Arrow"
"item.minecraft.tipped_arrow.effect.thick": "Thick Tipped Arrow"
"item.minecraft.tipped_arrow.effect.mundane": "Mundane Tipped Arrow"
Confirmed in 1.16.1 and 20w30a.