My enchantment table (E) is surrounded by 15 bookshelves (1 resp. 2 tall) and torches (T) in this layout (see layout.png):

.222.
2T.T2
2.E.2
...T1

Despite the three torches (T) diagonally from the enchantment table (E) the third slot offers a level 30 enchantment (see problem.png).  I'd expect only the six bookshelves straight to the sides of the enchantment table to be having an effect and the available enchantment levels to be lower, just like when the nine bookshelves "blocked" by the torches are removed (see expected.png).  This worked as expected up to and including v1.18.1, I'm only encountering the problem in v1.18.2.