TT Stick pass

So, I did one of the TT events last night. With TT bikes as it’s a non draft event. So why did I experience sticky passes? Had up the power considerably to pass a rider which shouldnt need to happen when on a TT bike in a non draft event. Surely this would affect the overall speed and therefore the result times etc. Also upping the power on a TT is difficult is such a short sharp race where your already on your limit!