isaffine and islinear not handling differentials correctly

[n0rbed]

@variables x y t
D = Differential(t)
Dx = D(x)
expr = Dx * x + Dx*t - 2//3*x + y*Dx
Symbolics.isaffine(expr - Dx, [x])
#  ERROR: Failed to apply rule (~f)(~(x::isidx)) => if haslinearity_1(~f)
Symbolics.islinear(expr - Dx, [x])
# ERROR: Failed to apply rule (~f)(~(x::isidx)) => if haslinearity_1(~f)

However, checking if its linear with respect to Dx outputs a correct answer:

Symbolics.isaffine(expr - Dx, [Dx])
# true