String Interpolation discrepancy

So I decided to boot up Linqpad to do some simple diagnostics on the different ways to format strings. During this, I noticed string interpolation was extremely slow. I originally assumed this was an issue with string interpolation but after running the same code in .NET 5, 4.7.2, and 4.6, it appears to be an issue with Linqpad. I have turned of compiler optimization as well in all environments only to get the same results. Would anyone know what I am potentially missing here that could be causing this discrepancy?

Linqpad run:

.NET 6 run:

var foo = "test1";
var bar = "test2";
var baz = "test3";
var bat = "test4";
var count = 100000000;
var test = string.Empty;
var sw = Stopwatch.StartNew();
for (var i = 0; i < count; i++)
{
    test = foo + bar + baz + bat;
}
Console.WriteLine("Plus: " + sw.ElapsedMilliseconds + "ms");
sw.Restart();

for (var i = 0; i < count; i++)
{
    test = $"{foo}{bar}{baz}{bat}";
}
Console.WriteLine("Interpolation: " + sw.ElapsedMilliseconds + "ms");