You could try new foods. I certainly doesn't hurt to get some variety. 3 months is quite some time at those temps though. Some snakes are more light-sensitive than others'. I know that even if I gave warm temps, if they didn't get full spectrum, or if they got short days, it made a difference in their feeding habits. If they are healthy weight, getting full spectrum lighting, at least 12 hours (depends on ssp.) warm temps, etc. It could be that sometimes the hard parts of the food (bones, hair) build up in the stomach since they digest slower, and the snake could just need some time to digest that stuff. It also seems to help if you just give up and don't offer anything for several weeks. If you offer the same food too often, they smell it, and they're like "this again?". Let them NOT smell food items for 2-3 weeks and they're like "oh WOW, FOOD!"

but 3 months seems a little too long for comfort for a yearling unless brumating. Again, having weight records would help. I did things the old fashioned way - observation using my senses. I could tell if my snakes were losing weight or otherwise declining in any way. Still, if it's been that long and feces are all evacuated, it might be a good time for little rest. Unless your snake has lost significant weight that's what I would do. I never give them year 'round summer. I believe that for long term health, the seasonal fluctuations are just as important as day/night fluctuations, even if you don't full-out brumate, it's good for them to slow down for a few months each year. Opinions vary though, and different species/ssp would have different responses to seasonal stimuli. A full spectrum bulb, bright enough, for long enough has worked wonders and can be as important to appetite as temperature is.