Premiere Pro audio rendering madness

I have been working on a 2 1/2 hour film in Premiere CC 2017 and whenever I need to export a small clip, say 10 sec long it begins rendering ALL the audio which can take up to 15 mins to complete. I only want to export 10 sec so I'm not sure why this is necessary. Be that as it may I have tried simply rendering all there audio myself. Once I do that I can export the clips without this happening. However if I exit the program and re start it again all the audio render files seem to disappear as it again renders all the audio over again.

I do not know if there is a solution for this other than update to 2018CC which is not really a good option in the middle of a project. I know I can keep two different Premiere versions I would just prefer for this not to happen.

It happens in every project I am working on, all of them use a variety of footage and audio sources which may be the cause. That does not explain why it keeps having to re render all the audio over and over and over.

Any help would be appreciated.

Thanks

MacPro 2012

3.33 GHz 6-Core Intel Xeon

32 GB 1333 MHz DDR3

NVIDIA GeForce GTX 680 2048 MB