Hi Darren,
Thanks for posting in the community. We are happy to help you.
Currently, based on the way forms were created, there are two ways for forms to sync data to Excel workbooks (sync responses in real-time Or sync responses only when opening the workbook in Excel for Web). Per your description, it appears that your form uses the second method. To check your form type, I would like to know what the Excel icon of your form looks like.
You can go to Forms for the web (https://forms.office.com/), open the form, click the Responses tab, and check the Excel icon. Does the Excel icon look like the first icon or the second shown in my screenshots?
We look forward to your response. Thanks for your cooperation.
Sincerely,
George | Microsoft Community Moderator