FindSessions returns EOS_InvalidParameters on first run

[xuelongmu]

Environment

Project Version: 0.0.3
EOS SDK Version: 1.7.0
Unreal Engine Version: 4.24.3

Other software/plugins that *might* be the cause of the issue?

Steps to reproduce

1. Login via AccountPortal
2. Create new SearchSettings object and call FindSessions. These were my settings:

    bIsLanQuery = false;
    MaxSearchResults = 10;
    PingBucketSize = 1000;
    QuerySettings.Set(FName(TEXT("bUsesStats")), false, EOnlineComparisonOp::Equals);

Expected behaviour

Return successful search with empty results.

Actual behaviour

On the first run, when setting the custom bUsesStats search parameter in the UpdateSessionSearchParameters method in OnlineSessionInterfaceEpic.cpp, the following line creates an EOS_InvalidParameters error:
EOS_SessionSearch_SetParameter(eosSessionSearch, &eosParam);

In order to make the error more visible, I modified the line and added a check as follows:

auto eosResult = EOS_SessionSearch_SetParameter(eosSessionSearch, &eosParam);
if(eosResult!=EOS_EResult::EOS_Success)
{
    error = FString::Printf(TEXT("Cannot update search setting: %s - Error Code: %s"), *param.Key.ToString(), UTF8_TO_TCHAR(EOS_EResult_ToString(eosResult)));
}

which gave the following log output:
LogOnlineSession: Warning: OSS: Cannot update search setting: bUsesStats - Error Code: EOS_InvalidParameters

The second time I call FindSessions, there is no error and the search completes successfully with empty results.