StringSet last digit of uint64 value is wrong

I have an issue where StringSet messes up the last digit of my uint64 value.
I want to store 142205255210238005 but redis-cli > get key1 returns me 142205255210238000.

See here an example :

using System;
using StackExchange.Redis;

namespace redisUint64
{
    class Program
    {
        static void Main(string[] args)
        {
            ulong value = 142205255210238005;
            var conn = ConnectionMultiplexer.Connect("127.0.0.1");
            var db = conn.GetDatabase();
            db.StringSet("key1", value);
            var retVal = db.StringGet("key1");
            Console.WriteLine(retVal);
        }
    }
}

Stackexchange.Redis version 2.0.571
Redis server version 5.0.4
.Net Core 2.2
Arch linux 64bit