Why did Lord Chaitanya not give the Hare Krishna mantra to Tukaram Maharaj?

If lord Chaitanya is the spiritual master of Tukaram Maharaj then why is it that he was given a different Mantra than the Maha Mantra
though the Upanishads claim the maha mantra to be the only remedy for removing the effects of Kali……………………………If it’s
just because “Ram Krishna Hari” also is God’s name only, then one may say that he’ll chant that only because that’s shorter and more
verifiable as whole village actually saw tukaram maharaj going back to Godhead.