The #minecraft:sand tag has two items set to "minecraft:suspicious_sand". This leads to no problem, though.
<version jar>\data\minecraft\tags\items\sand.json:
{
"values": [
"minecraft:sand",
"minecraft:red_sand",
"minecraft:suspicious_sand",
"minecraft:suspicious_sand"
]
}
Confirmed, goes for both the block tag and item tag.
Do note, that while it has no impact, other reports like this were accepted and fixed.