Symbolic solve, 'maxdegree', python error?

Does the symbolic toolbox solve not handle the MaxDegree option?
Trying to reproduce the matlab examples here:
https://www.mathworks.com/help/symbolic/find-asymptotes-critical-and-inflection-points.html

Other than having to replace fplot with ezplot, I get to the line
trying to solve for inflection points with:

inflec_pt = solve(f2,'MaxDegree',3);

and I get:
>> inflec_pt = solve(f2, "MaxDegree",2)
error: Python exception: AssertionError
    occurred at line 25 of the Python code block:
    assert stage == 0 or stage == 1
error: called from
    pycall_sympy__ at line 178 column 7
    solve at line 182 column 9

the help doesn't list name/value option pairs, so without jumping into
the python code I don't know if the error is just that I called an
unsupported option or if there's some other problem.

(octave 5.2.0, symbolic 2.9.0, python 3.7.0 (nonbundled) , sympy 1.3)