Hotpoint fridge. Hi Ginko, Reference my Hotpoint/Ariston/Zanussi fridge. MSAA44. There is no

Question

Hi Ginko, Reference my Hotpoint/Ariston/Zanussi fridge. MSAA44. There is no removable plate inside the fridge to get at the thermistor but what I did notice is that where the ice was forming on the back panel the inside lining is raised away from the insulation like a large flat bubble. Could this be a cause? Thanks for all your help John