Champions appearing for a spilt second then disappearing again

Hi, I come accross a bug where an enemy champion just appears (sometimes right next to you) for a second and then suddenly they are gone again. It started happening to me but only on the Minimap where I would see the enemy jungle bot side (sometimes in the fog of war) and then they would gank top moments later, but recently this has started happening where I now see the champion on the screen near me rather than just on the Minimap. Just wondering if anyone else has had a similar problem?