This seems to still be a issue when using refcursors in 23.9
See this repo for code that procues the error: https://github.com/mvn-dips/OracleTelemetryError

Unhandled exception. System.Exception: TTC Error
at OracleInternal.TTC.TTCExecuteSql.ReceiveExecuteResponseAsync(Accessor[] bindAccessors, Boolean bHasReturningParams, SqlStatementType statementType, Int64 noOfRowsFetchedLastTime, Int64 noOfRowsToFetch, I
nt32 longFetchSize, Int64 clientInitialLOBFetchSize, Int64 initialLOBFetchSize, Int64 initialJSONFetchSize, Int64[] scnFromExecution, Boolean bAllInputBinds, Int32 arrayBindCount, Boolean bDefineDone, RER_RefAndOutParamArgCtx refOutArgCtx, Boolean bReadSqlId, Boolean bLOBArrayFetchRequired, Boolean bAsync)
at OracleInternal.ServiceObjects.OracleDataReaderImpl.FetchMoreRowsAsync(Int64 noOfRowsToFetch, Boolean fillReader, Boolean returnPSTypes, Boolean bAsync)
at Oracle.ManagedDataAccess.Client.OracleDataReader.ReadInternalAsync(Boolean bAsync, CancellationToken cancellationToken)
at Oracle.ManagedDataAccess.Client.OracleDataReader.ReadAsyncHelper(CancellationToken cancellationToken)
at Program.<

$>g__ExecuteDummyCommand|0_0(OracleConnection oracleConnection) in C:\GIT\OracleTelemetryError\OracleTelemetryError\Program.cs:line 50
at Program.$(String[] args) in C:\GIT\OracleTelemetryError\OracleTelemetryError\Program.cs:line 31
at Program.(String[] args)

Originally posted by @mvn-dips in #416