If you're picking a spot, then you're probably missing left for one of the many general reasons RH shooters miss left, as opposed to anything specifically having to do with the deer target. Perhaps it's manifesting itself on your deer target because of some added self-imposed stress that's causing you to lose concentration and awareness of what you're doing during that particular shot.
This is a general checklist of why RH shooters commonly miss left (I'll omit equipment issues, as I don't see how that could be a factor here, as gear seems to be immune to psychological pressures). It probably wouldn't hurt to do a general checkup of your form at the time you're shooting at the deer target, to see if anything is slipping:
- Torqueing the bow or the string
- Dominant eye not over the arrow
- Not getting your string forearm back behind the arrow, i.e. not coming all the way to full draw
- Shoulders not aligned with target at full draw
- Moving your head during the shot or peeking.
If you're doing any of these things (or something else I didn't list) you're obviously unaware of it, or you wouldn't keep doing it. So you may have to have someone else observe you, or video yourself, to actually see what's happening.