It’s not a SHA256 hash.
Related topic: Cardano-cli hash-script-data
ScriptData code: cardano-node/ScriptData.hs at 2124712b360b37b5d590279a4674d504dd32eda5 · input-output-hk/cardano-node · GitHub
ScriptData doc: Cardano.Api.ScriptData
CBOR: rfc7049
Hero: @bwbush