I cannot find any reason to put a comma after "issues."
Please note that "Lease" is a name.
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The comma after issues is paired with the comma after rates. The phrase "such as interest rates" is a parenthetical phrase, and English often uses a pair of commas or dashes around them.
Without the parenthetical phrase:
A shrewd speaker, Lease presented complex issues in a confident, straightforward, manner...
The parenthetical phrase "such as interest rates" gives an example of what the author means by "complex issues".
You could argue in this case that the parenthetical phrase is short enough that it doesn't need commas, but it's a matter of style, not a hard rule.