Hi, yes, it sounds like you may be running into an issue with imagery post PB4.00 where the proper offset has not bee applied. This image service is sourced from the Microsoft Planetary Computer and you can read more about this here. For now, you will need to apply the appropriate offset as part of your workflow.
The Sentinel-2 Level-2A service is currently in beta. As part of our efforts to move this out of beta and into general availability, we will also be applying that offset on the service to normalize the data on the fly so that users will not need to worry about doing this. We anticipate releasing these changes in 2024 Q2. Further down the road, once Sentinel-2 Collection 1 imagery is available on Planetary Computer, that imagery will be provided through this service.