@ZoeHui-MSFT - thanks for your help. It's fixed now. apologies i wasn't well.
What I discovered that if you type nt service and search for the account it does not show up, howerver it you type nt service\sqlserveragent and search , it replaces with SQLSERVERAGENT. This means we can't find the account manually, good to know anyway.
Kind Regards,
Mudit