Issues with small borders on layers

[TheBigC]

Hello,First threat here so sorry for possible errors. I have a problem while im printing stuff. Im a total noob on this world but even trying to find a solution i dont find anything. My problem is that my printer somehow make small borders on the layers of the piece im printing on a determinate point of it. It is always on the same point and at start when i made the first pieces(when i bought my printer) i didnt have this problem so i dont know what is happening. I tried to rise tempeture to 210?C because i use PLA but it didnt work so i change parameters to make the piece more slow(less speed i mean) but nothing change so i dont know what to do. Better a image to show it.(sorry for quality but black dont be a good color to show imperfections and have to find a light). The program i use is Cura and my printer is a Creality Ender 3 Pro. Hope someone can help me. Thanks and greetings.