Shopping Impression Share in Looker Studio differe...

I am facing an issue with vizualisations on Looker studio. We use visualisations in Looker studio to see the auction insights of our Pmax campaigns from Google ads and more specifically to look at shopping impression share. However, historical data have changed and don't match our google ads data anymore. It seems that the shopping impression share of our client and competitors have been diminished on the visualization compared to the data that was diplayed previously. It seems there is an issue somewhere and our data from google ads are not displayed correctly anymore. We've already tried many things to troubleshoot the issue but cannot find any solution

Did someone face the same issue or could help?

Shopping IS (May 2024) in Looker Studio a few months ago: