TPOT MDR - no usage of MDR?

I've been running TPOT with the TPOT MDR configuration, and in multiple runs I see no usage of any of the MDR functionalities - MDR, ReliefF, Surf, etc. For example, the following pipeline came from a run with a population of 250 for 25 generations:

exported_pipeline = make_pipeline(
make_union(
FunctionTransformer(copy),
StackingEstimator(estimator=ElasticNetCV(l1_ratio=1.0, tol=0.01))
),
ElasticNetCV(l1_ratio=0.15000000000000002, tol=0.01)
)

I have done similar runs with 100 individuals for 15 generations using a different random seed, and I see very similar results, but I've never seen one of the MDR functions appear in a pipeline.

Do I need to supply an additional argument that I'm not aware of to enable MDR and skrebate functions?

Versions:

tpot = 0.11.5
skrebate = 0.6
scikit-learn = 0.22.1
scikit-mdr = 0.4.4
scipy = 1.4.1
numpy = 1.17.5