have there been any changes to this part of kx.ser after 1.5.31, 1.5.32, 1.6.0 and 1.6.10 are all affected by an issue that the valueSerializer is always a UnitSerializer https://github.com/Kotlin/kotlinx.serialization/blob/master/docs/serializers.md#custom-serializers-for-a-generic-type This is actually a very important issue preventing us from using 1.6.0 There is an update comment on this issue, containing more information I found: https://github.com/Kotlin/kotlinx.serialization/issues/1705#issuecomment-1001786343