disclaimer: i might be wrong, and it could just be the artist's art style
but there are some things i found quite odd:
-their usual style shifted quickly at a specific point in time (sometimes some artists actually decide to switch to ai)
-the skin looks overly glossy in almost every recent artwork they made and the nipples look weird, similiar to many posts of other users on patreon/fanbox who openly stated using ai, and nearly all of them come in batches of over 50 images, and i personally never found any artist who took the time to make 50+ variations of the same parent image (unless they really wanted to or they thought it could repay the time they spent)

but the thing that stands out the most in my opinion is the speed with which they crank out artworks, on their fanbox the recent posts go as follows
-85 differences on the 1st of april 5pm
-70 differences on march 31 at exactly 5pm as well
-1.5 hours "making of" video
which could be fake according to a user replying to a comment that said "I am so sorry for ever doubting you", to which they replied "try searching for PaintsUndo" (under the post 128694804 on pixiv)

i then searched for that program,which led me to its github repository, and it produces a video of the process of creation of an artwork by generating a user-selected number of keyframes from a single image (most likely by lowering saturation and detail, and generating the lineart), and them animating the process.
i was able to generate some 4 keyframes of an image i had on my hard drive on huggingface, but since the video generation is gpu heavy, i couldn't proceed with the video. and i didn't want to install it on my hard drive, since i have a 4070ti, not a 4090 (i need 24gb vram to run it properly) and i can't find an actual use for that in my case other than jesting with my friends with it.
- then another 20 variations on 29 of march, precisely 5pm as always

and they referred to themself as a single person on fantia
"Hello, my name is Dicko!
Thank you to all my fans for your continued support!
I aim to update about seven times a week!"
--machine translated

so, either they are using ai to post that much content so often, there are more than one person working behind that account, or they draw so fast they start breaking reality itself

with that said, i dont want to accuse anyone, nor am i claming to know for sure, since i couldn't find much evidence to either confirm or debunk this theory for certain.
so i'd like someone with a bit more experience to verify and take actions if needed
i'd be glad to be proven wrong with facts, so please if i said something incorrect or missed something, just let me know.

thanks.