In the Memory store sorted map add or overwrite data section the sample sorted table given has the table keys start with an uppercase letter
{Key: "player1", Value: someValue1, SortKey: -1}
where the actual data is in lowercase like other data store tables. Screenshot from studio output:
I suggest to change the example to reflect actual return values from :GetRangeAsync(). Had some trouble debugging as I had tried to transform the “Key” to “key” to interface with other datastore functions
Page URL: https://create.roblox.com/docs/cloud-services/memory-stores/sorted-map#add-or-overwrite-data