I'm like 90% sure this is bubuzuke. I remember reading some posts in very early 2018 from him talking about how he was taking on more serious/mainstream work that would prevent him, contractually, from continuing to make fanart or work independently as a freelance artist. Then he just kind of disappeared. Checking his twitter the very last tweet he made was in may 2018 which was a retweet of pandami, whose account was also created on may 2018. It's also quite weird that this artist's very first post was for making fanbox/fantia content. I think he abandoned his old account and name and tried to change his style a bit so that he could continue making fanart.