Providing your ESA claim pre-dates March 2017 then the WRAG component is payable in UC and you do not need to qualify for it under UC, your existing award should be transferred, your UC advisor needs to contact the ESA department for details of your award.
ESA is paid fortnightly, uC is paid monthly both in arrears.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems