The main controversy about the 19th Tirthankar Mallinath is his gender. There are two traditional views among Jain communities:

• Śvetāmbara view: Mallinath was a female, known as Mallī Devi. She is celebrated as the 19th Tirthankar in female form, teaching that women can attain liberation directly.
• Digambara view: Mallinath was a male Tirthankar. Digambaras hold that all Tirthankaras are male and would attain moksha in a male body.

Both traditions agree on Mallinath’s path to liberation and his lanchhan (symbol), but differ on whether Mallinath was a woman or a man. This difference is a well-known sectarian debate within Jainism.

You can read more here and see related discussions in Jain Knowledge’s Mallinath materials .