Maxima simplifies 2 * 2^(1/3), so

(%i1) tex(2*2^(1/3));

$$2^{{{4}\over{3}}}$$

I don't know what you did, but if you set simp to false, don't expect

Maxima to work correctly:

(%i2) block([simp : false], tex(2*2^(1/3)));

$$2\,2^{{{1}\over{3}}}$$

(%o2) false

A workaround for this case

(%i3) texput ("*", " \\cdot ", infix)$

(%i4) block([simp : false], tex(2*2^(1/3)));

$$2 \cdot 2^{{{1}\over{3}}}$$

(%o4) false

(%i5) (texput ("*", " \\, ", infix), tex(a*b));

$$a \, b$$

(%o5) false