Elevation and slopes completely off

Since about a week, cumulated elevation are completely off when planning a route. For instance, à route planned and forecasted 1000m cumulated elevation is actually only around 500m (no bridge or tunnel). Did no change on the app and could not find any solutions in the other topics. Slopes are also off (25% slopes obtenir forecasted) but this has been the case since the beginning (2 months use).

I really need help, especially for elevation has planning is then quite difficult (and i'm on a bike trip)

Thanks !