It is working as you intended:
julia> A[Ind] .= 88
4-element view(::Vector{Int64}, [1, 3, 4, 6]) with eltype Int64:
88
88
88
88
julia> A
2×3 Matrix{Int64}:
88 88 3
4 88 88
Note that what Julia returns from an assignment expression isn’t always going to be the value on the LHS, but that doesn’t mean the assignment didn’t occur!