threads hanging on production when using transaction

[pianoman4873]

Hello,
I have a synchronous method which does the following -

var transaction = _connectionMultiplexer.GetDatabase(0).CreateTransaction();

var returnValueTask = transaction.HashSetAsync(key, KeyValuePairsToHashEntries(keyValuePairs));

transaction.KeyExpireAsync(key, expiry);

var success = transaction.Commit();
if (!success) throw new Exception("transaction failed");

return returnValueTask.Result;

I've load tested it locally (100 threads doing the same to either the same key or different keys ) everything seems to be working fine,
but we've seen in production env that pretty frequently the transactions don't seem to complete ( or take very long to complete ).

Am I doing something wrong in the code ? ( other than the method being synchronous which is a prerequisite ).
Could you suggest an alternative to simulate atomic writing of both the hash and the expiry ?

Thanks in advance !