Morning Sheddy and welcome to the Utilita Community 😀
Sorry to hear that you're experiencing these issues - there could be several reasons this is happening - from bad signal between your In-Home Display and main smart meter, to having technical issues with the two linking.
As this is account specific - and the Community is for general non account specific issues - this would usually require you to speak to a CSA advisor on Live Chat, Phone etc. However, as you say this has been ongoing and there has been no resolution - on this occasion, I can escalate this to our Customer Experience Team to investigate.
Please could you send me a private mail with your full address and/or customer reference number.