Please help with maxHitPoints

I am trying to set the maxHitPoints of the player with a script. I have tried everything. If I change it using player.maxHitPoints = 500 it will change for a millisecond then it's right back to 100. I have even tried the helm template from the tutorial here:
which works when you just load the project and run it but when I add it to my scene it does the same thing changes maxHitPoints for just a millisecond then it's right back to 100.

Thanks in advance for any help offered. I have been trying to figure this out for a day now. I am sure it's something simple I am not doing.

It's hard to tell without seeing your code, but by the looks of it there seems to be some other active script that resets the value back to default. If you are using an external editor, run global search and look for maxHitPoints.