Positive NPV yet IRR < WACC

[Acecombat]

Hi Guys,

I'm having an odd result in excel. I have a project with a positive NPV but the IRR excel is giving me (both IRR and XIRR formulas) is LESS than the WACC. It does not make sense, if NPV > 0 then IRR should also be > WACC.

The CF's in the project do change signs in between and go from negative to positive then negative and positive again multiple times (4 times). Could that be causing the IRR calculation in excel to go wrong?

Any help will be appreciated.

Regards