following produces the same hash value in powerbuilder and .net:

//Powerbuilder Hash: 

blob lblb_hash
string stringtohash, HashBase64

lblb_hash = lcr_crypt.sha( SHA3_256! , stringtohash )
HashBase64 = lcdr_coder.base64encode( lblb_hash )

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//.net 6.0 Hash:

//GitHub - dariogriffo/sha3.net: C# port of Keccak, known as SHA3

using SHA3.Net;  //download via nuget SHA3.net  (there is a version that does not have .net in the name that is NOT the one i downloaded)

string HashBase64;
using (var shaAlg = Sha3.Sha3256())
{
var hash = shaAlg.ComputeHash(Encoding.UTF8.GetBytes(stringtohash));
HashBase64 = System.Convert.ToBase64String(hash);
}