Is the AI wrong on this occasion? Is it right due to the White stones around O4 or is this simply a candidate for addition to Joseki?
There are 164 hits on Waltheri.
Even if only 75 of them have the right stone colours and a fairly non-contextual position, that still seems like joseki to me, so either an Ideal or Good move depending on more subtle factors.
By the way, you want this thread in the dedicated Joseki category.
Category changed. Thankyou bugcat.