steps

• Create an sbt project and add "-deprecation" in the scalacOptions
• Import it with BSP (in Metals for instance)
• Type something deprecated and save the file
• A warning is reported
• Change another file to trigger a recompilation
• The previous warning disappears

problem

The BuildServerReporter resets all files after compilation even the ones that has not been recompiled (thanks to incremental compilation).

expectation

The warning diagnostics should persist until the file is recompiled.