as above.Is it setup correctly? Scope, pins? If it is too small you might try opening it up some or use a clarifier peep indoors. But if it worked outside it should work inside unless you have changed anchor point or the peep as slide on the string causing it to be turned when you draw it back.

I may be just that it is too smal an appeture. But that would not make any sense. Lighting will cause you not to see clearly through your peep if it is too bright behind you and dim in front at the target.Which is sometimes the case.But you say you are shooting somewhat well on a Fita target which is rather small.So you must be seeing something through the peep, right? Scope? Pins? Scope would cause a blind spot if the peep is too large if you chnaged your site that is but not if very small. Tough to diagnose from what you have stated.But can relate very well as I have the same problem outside with high powered scopes over 4x, but different problem all together. Give complete site setup. Peep size,site used, single cam,wheels etc. maybe we can figure this out.

Wearing a shade would only help if the light was shining toward your face,from the front of the peep not the rear. Most inside lighting comes from behind the shooter and is lit down range but the bale would show some what dimmer as of range being 18 meters or 20 yards from the line. If your peep is covering the site ring it is probably a hunting peep 1/8"-1/4". The larger ring supposedly forces you to center the pin in low light conditions, supposedly. You say you just go off instinct, that would mean you don't use your peep or sight really. Are you centering your nose on the string and shooting both eyes open? If not centered you raise the possiblity that your nose is covering the view of the peep slightly. Also, are you wearing glasses? Glasses will distort the veiw of the peep because your head is angled slightly causing you to look between the glass frame and your nose.

Contacts would only effect your peep alignment if you had bi-focal or tri-focal lenses. You evidently are placing your nose along the string consistant and viewing your site picture right, while 375 is not a great score it is not bad either. Holding your picture sight with placement of our nose looking on either side of the would determine your left or right impacts. Your anchor would determine your height. Are you going to Vegas this month? If so have a great time it is truely a shooting wonder. The best I have ever done was 589/600 in MBHFS 1991 I probably will never make it back there. Awesome place and event to go to if you have the chance go.