Pretty blatant one for "donut" versus "doughnut": has one spelling in the item name and a different one in the description.
they/them/theirs, please.
I heart this thread (I once wrote up tons of apostrophe issues, gray v grey issues, old species name issues, etc) except for doughnut.
"In the US, both are used, with donut indicated as a variant of doughnut.[137]"
It's Donut. Every store around me is Donut. I am in TX, for the record.
I get Doughnut, it's Germanic (though even the Germans don't usually use it) but it just reads... awful to me. Also, 'doughnut' is listed as a British spelling as well. I don't think it's as cut and dried as the dropped u or other examples on this list, at all.
Even Google seems to agree. Donut > first result "donuts near me". Doughnut > first result "doughnut vs donut", then "doughnuts near me".
Doughnut is technically the correct, dictionary spelling of it. Donut is incorrect, it's even underlined as a misspelling. Donut is popular because of Dunkin' Donuts, but it's still not correct.
Also wondering if the spellings of the other items will be taken care of, there's so many in the OP now it's hard to edit :(
Since this thread is still relevant, there's dark matter vs. darkmatter items that need to be fixed.
Examples: vs.
This has been bothering me off and on for a while:
I'd prefer they all be "Limited Edition Delish name here" because it's easier to search for them that way.

I found some, may look for more later:
There are a couple item descriptions that use centre instead of center. and then this cw
and then there's a bunch of item descriptions that still use favour/favourite instead of favor and favorite.
artefact vs artifact Spelled correctly in the item name and then incorrectly in the description.
behavior vs behaviour
jewelled and bejewelled vs jeweled and bejeweled
also the description of that one
the description in these
catalogue vs catalog item names also the desccription of this one the description of this one
cosy vs cozy item descriptions
fibre vs fiber item descriptions
humour vs humor item descriptions
I don't think any of these have been mentioned before. I don't want this post to get too long so I'm gonna stop here lol sorry it's quite a lot.

Some of the saheric headscarves are "leopard print" (leopard print elegant saheric headscarf) and others are "leopard" (leopard loose twist saheric headscarf)
hotdog vs hot dog and corndog vs corn dog
Is button-up vs button up a consistency issue or do they mean different things?

gummy vs. gummi (293 gummy vs. 34 gummi)
even occurs within items of the same type; out of the dire worm gummies, two are spelled 'gummi' and three are spelled 'gummy'.
gummi
gummy
[edit] and high tops vs. hightops vs. hi tops vs. hi-tops!! ridonculous!!!
Kora Pop Up Book (all other books are "Pop-Up Book")
argh I hate inconsistencies in items of the same type; some of this is aesthetic but that one can be seriously confusing. The same thing happened with the leopard saheric headscarves (in the post above you)

noticed this one while filling a tc -- "Antique (Colorway) (Item)" vs "(Colorway) Antique (Item)"
vs
thirty pieces of furniture are "Antique (Colorway) (Item)" (chairs and couches) and fifteen are "(Colorway) Antique (Item)" (day beds and dining tables). the divide is consistent through all five colorways (ashen, blonde, dark, light, and mild), but it does make it a little difficult to search for sets x;
I didn't see them on the list but we have both Snow Cones and Snowcones vs Should be Snow Cone, with a space. None of the flavors overlap so just fixing the spacing issue wouldn't be hard.
Top down I got through defense! Will continue more in the next couple of days, but I can't keep my eyes open any longer right now :P
that lack of the space really bothers me
1, no space, 2, it went from a freezewand to an icewand. this makes remembering the names so difficult :C
@ Ariel Thanks for getting through them!
There's still a lot of suggestions on this page that I've yet to add to the OP @ Luck reminder
[edit] Finally finished adding the rest that were on this page! the list became long again, sorry. New ones are denoted with the emojis!