this tends to happen if, for example, you warp to a stargate and arrive perpendicular to its longest axis. (perpendicular meaning "at a right angle to" like in a capital T)
Basically, the deviation on warping places you inside a cylindrical volume near your actual intended warp target. This is a rough guess, but I'd place that zone's length at about two thousand meters, and the radius at about one thousand.
Usually, this deviation doesn't make any difference, but sometimes, your landing point will be just outside the 2500m jump range of a stargate, or the 500m docking range of a station.
I don't think it can reasonably be called either a bug or a feature. It's just a product of the way warping works.
if you want to minimise the risk, try if possible to remember the orientation of what you're warping to. if you want to be absolutely certain that it will never happen, warp in parallel to your target's longest axis. Bear in mind though that taking the warp detour necessary to achieve this will take longer than just flying the three hundred meters or so and jumping normally. There are very few ships in the game that are simultaneously so fragile and so slow that being dropped a mere few hundred meters outside of jump range will result in death.
Your ship's size and mass have an effect as well - small ships are more likely to "fall short" than large ones because they decelerate faster, and are smaller, while larger, heavier ships will "coast" a bit further and their larger collision hull tends to wind up inside the catchment zone anyway.