In the creative mode inventory "Search" tab Redstone dust, Dried Kelp Blocks, and some others such as all sign types, are incorrectly placed (Dried Kelp Block is the perfect example, being placed with miscellaneous items. This is not the same in 1.15.2 as these items were correctly organised in that version. This I don't think is a side effect of new blocks being added, as things like the Lectern and Smoker, and chain are all correctly organised.