Due to how the data is presented in the Google Ads UI and how it comes from the API, you may see small discrepancies between the values of the "Top Impressions Share"- and "Absolute Top Impression Share"-related metrics.
The numbers shown in Google Ads' own UI tool are given as percentages with 2 digits after decimal separator, for example 97.25%. However the Google Ads API returns the same value to us as a ratio with 2 digits after decimal separator, for example 0.97.
This means that there can be differences in the results you see when pulling data with our tools and comparing it to what you see on Google Ads. Unfortunately, this is a limitation within the API that we have no means of fixing at our end. However, the differences should be fairly minor in most cases.