Reinstatement and backdating of Income Support in UCFS area

client lost their IS/CA as the person they cared for lost PIP. person they cared for has won PIP back at appeal backdated to original decision date, but area has since gone over to UCFS. The client can claim CA backdated again but how does the client get their backdated entitlement to IS when now in UCFS? (they have not claimed anything in the interim)

Anytime revision of the decision to stop income support - see CPAG pg 1296

Previously discussed here https://www.rightsnet.org.uk/forums/viewthread/11899/. I recently posted a request for feedback as to whether that worked but as yet no reply.