SharePoint list is not loading all items, so not all used choices are available when filtering on a column.

Question

Hi,
We are have a SharePoint list with around 500 items. We have a mix of text and choice columns. When opening the list we can filter on the text columns and find all items on the list. The issue is with the choice columns as they only shows the choices used in the first part of the list, not all the used choices on the list. For example we have also used the choice "Gas" in the column 'Risk Assessement Group', but it is only visible, if I scroll further down in the list.

This is a big issue, since it does not give a clear overview of the filtering options, and it takes too long to scroll all the way to the end everytime.