Async Methods overwriting previous call

Question

I am writing a console application wherein I'm using async calls to another method. I have the same call happening twice with different overloads. When I'm debugging I can see that the first call got the correct information but when the second call finishes the first call variable is overwritten with the second call's results.

Its literally 2 lines of code that are giving me issues.

var myParty = await _partyService.GetParty(Context.User.Id);
var compParty = await _partyService.GetParty(0);

myParty will initially have the correct values, but when compParty populates, myParty changes to match it.

edit: as requested my _partyService GetParty Class.

public async Task<List<CreatureBase>> GetParty(ulong playerID)
        {
            try
            {
                List<CreatureBase> party = new List<CreatureBase>();

                Dictionary<ulong, string> partyMembers = new Dictionary<ulong, string>();
                partyMembers.Add(0, "Testy");

                foreach (var pM in partyMembers)
                {
                    var cList = await _creatureService.GetCreatureList();
                    var c = cList.Where(x => x.Key == pM.Value).FirstOrDefault();

                    var newCreature = await _creatureService.GetCreatureStats(playerID, c.Value);

                    party.Add(newCreature);
                }

                return party;
            }
            catch (Exception ex)
            {
                return null;
            }
        }

as i said previously, this does return the 2 different results expected, but myParty gets changed when this returns the second result to compParty