c++ actor component causing cpu stall ?

Hi folks,
I have a BP project that I created a custom C++ actor component class from a vid tutorial.
I cloned the project and have been working on the clone.
PIE is absoloutely fine,
When I package the game and launch…
CPU activity is intense for around 4 mins with frames dropping to single figures,Maxed on all 4 cores
Once it has settled down (4mins) the project works fine with frames smooth in the 80-100 region and minimum cpu load

My question is do I need to recreate the c++ class in my cloned copy ?

Thanks Paul G