Manage migration from contribution ESA has forced me over to new style ESA

Hi I have had to transfer from Contribution ESA to UC due to me being on housing benefits. After a fight I’ve got UC to add Rule 19 as I’m in support group on ESA so they now agree I don’t have to send in Fit notes .. and my commitment didn’t state any work related rules .. however I’m now bring told that because of my UC migration I now have to transfer from Contiribution based ESA to New style ESA .. I have to have a tel interview for this next week and they state on letter that I will have to (1) explain how my disability / illness effects my ability to work .. (2) provide medical proof of this And (3) agree to tell them if my circumstances chsnge . Ok (3) makes sense but I’m already in the support group for ESA and have been for years why am I being asked to explain it all over again and to provide evidence again when I’m already in support group .. I never requested to transfer from contribution based ESA to new style ESA it was triggered by my UC transfer .. can they make me do this all over again , I’m protected on UC transfer as I’m in ESA support group but seems I’m not protected by any changes triggered at ESA ?? that I will have to provide medical evidence .., and

So does that mean at the tel interview I can just tell them I’m in the support group and I won’t be asked the questions on my letter related to work etc or do I have to go through all the ways my disability effects me with them all over again and provide them with medical proof ?