Do you have it zeroed exactly to start with, or have it shooting an inch high for the point and shoot?
What a lot of people don't seem to realise is if they have it set an inch high at 100 yard on base mag, then in the field double up on the zoom for the shot placement, then the poi shifts to double what you had if set at on base mag.
Switching between zooms from what you originally had it zeroed at will change the poi unless you have it perfectly zeroed.
Its always worth having if zeroed on the highest mag you are likely to shoot with, this way the distance it can be out is lessened with less mag.
Have to say on my Tikka 243 with a sporter barrel I could find my poi off a little between zero sessions. I wasted a lot of time and ammo chasing zero's until I did some thinking and found the main culprit was myself and my inconsistancy in hold taking the shot.
If you are a fox shooter, on normal ground then you dont get a massive amount of practice in the field, usually also without the opportunity to spend time on a shot checking your fundamentals.
It can take myself a few zero sessions to be 100 percent happy with my zero for longer shots on fox, taking the average poi between these zero sessions has eliminated my inconsistancy.
It gets left well alone at that point until I have a mishap in the field.