您可以尝试增加Javascript客户端超时。

hubConnection.serverTimeoutInMilliseconds = 100000; // 100 second

如果signalR断开连接，您应该尝试重新建立连接。连接可能会由于其他几个原因而断开，包括用户切换网络。例如，如果用户正在使用Hive电话并且连接到家庭/办公室wifi，但是走出，其然后连接到Hive数据连接。
您也可以参考以下类似案例的链接：How to increase timeout setting in ASP.NET Core SignalR v2.1?

var userId = {
    Userid
};
var query = (from og in context.OPERATORSGROUPS join gr in context.GROUPSRIGHTS on og.GROUP_ID equals gr.GROUP_ID join ap in context.APPRIGHT on gr.APPRIGHT_ID equals ap.APPRIGHT_ID join a in context.APP on ap.APP_ID equals a.APP_ID join o in context.OPERATORS on og.USER_ID equals o.USER_ID where og.USER_ID == userId select new {
    USER_ID = o.USER_ID, APP_ID = a.APP_ID, APPLICATION_NAME = a.NAME, APP_RIGHT = ap.PERMISSION, DESCRIPTION = ap.DESCRIPTION
}).Union(from oar in context.OPERATORSAPPRIGHT join ar in context.APPRIGHT on oar.APPRIGHT_ID equals ar.APPRIGHT_ID join a in context.APP on ar.APP_ID equals a.APP_ID join o in context.OPERATORS on oar.USER_ID equals o.USER_ID where o.USER_ID == userId select new {
    USER_ID = o.USER_ID, APP_ID = a.APP_ID, APPLICATION_NAME = a.NAME, APP_RIGHT = ar.PERMISSION, DESCRIPTION = ar.DESCRIPTION
}).Distinct().OrderBy(x => x.APP_ID).ThenBy(x => x.APP_RIGHT);