I want to take value from name node and fix node using a lambda expression.
<Issue>
<name>asdasasdasd</name>
<fix>zxcczxczxczzxc </fix>
</Issue>
My try was
GlobalVariables.issuesList = doc.Descendants("Issue").Select(s => new IssueModel(s.Value, s.Value) { }).AsEnumerable();

Your question is far from clear, but I suspect you may want something like:
// I would strongly discourage you from using global variables...
var issues = doc.Descendants("Issue")
.Select(x => new IssueModel((string) x.Element("name"),
(string) x.Element("fix")))
.ToList();
The ToList() call will force immediate evaluation of the query; without it, it would be reevaluated every time you iterate over issues.
Note that if the name or fix element is missing from an Issue, with the code above you'll get a null reference instead. You could instead use x.Element("name").Value (and ditto for fix) in which case you'll get an exception immediately if the element is missing.
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