Lagging when looking at one side in external view

When flying the default C172 (no g1000), in the external view, if i look to any side, the fps is normal (~40-60), but when I look to one side (it varies, sometimes left, in front, right, etc) the fps drops massively down to like 10-15. I googled about this and nothing came up so just wondering if anyone had the same issue and if it can be fixed.