firmware 1.50 and 1.51 are no longer Roon Ready compliant, as they have been modified by Mytek’s ex-partner HEM (that’s who is “Mytek europe”) in a manner that makes them non-compliant.
Please see here for more info, and Roon’s official advice to not update to any firmware releases for Mytek products until this mess is sorted out. If you’ve already taken an update, please email them as well (email address is in the above mentioned post), as they can help get you sorted out.