1) Out of pokeballs? Navagate to Settings>PokeStop and manage the "Skip Pokestop if we have more than X Pokeballs."
2) Idle sitting on one place but NOT taking a break? Navagate to Settings>PokeStop and manage both your "Skip Pokestop if loots are greater than X has a reasonable number." In my opinion 45 is just too low. Also check your "Skip Pokestop if we have more than X Pokeballs."
3) Are you moving around but not looting pokestops? You may not be able to intereact with pokestops because you are too far up. Change Elevation to 10 or to be more acuraate:
4) Can't see pokestops at all? Ensure your operating radius is not 0 with its feature checked. A good distance is about 200. (Settings>General "stay in radius of #")
If I've been helpful please consider giving me a thumbs up, and thanks for chosing PokeFarmer.