2D Character gets stuck while crossing 2 plane tiles

Hello everyone, today I started noticing that my character was a bit shaky on the Y axis while running on a simple plane (series of square tiles), and I checked in the inspector at runtime and I actually found out some slight variations on the Y of the transform. I have a box collider for the top and a circle for the feet, so I tried to remove the circle and add another box for the lower part. The Y movement finally stopped, HOWEVER now the character randomly gets stuck when crossing two adjacent tiles. Not quite randomly, I noticed it happens sometimes when I change direction, it must be a combination of position (relative to the end of the tile) and character velocity that triggers this. It really makes no sense to me, since the tiles have a dimension of 1 in unity, and their collider is also 1x1, plus I placed the tiles perfectly one next to each other using vertex snapping, and at integer positions just to make sure unity wasn't doing some rounding error, so the character should slide with no problem. Both character and tile materials have 0 friction and bounciness. Also they have rigidbodies, with fixed angle, and the tiles are also set to Is Kinematic. I spent the whole morning doing tests changing parameters with no luck, I even doubled the tiles collider size (so they overlap), and the player still gets stuck at the boundary. Basically when it gets stuck, even if I press D the animation runs but the caracter doesn't move, to move it again in that direction I have to step back first. Here's the code for the movement, very simple:

 float move = Input.GetAxis ("Horizontal");
 rigidbody2D.velocity  = new Vector2 (move * maxSpeed, rigidbody2D.velocity.y);

Sorry for the wall of text but I wanted to give you as much information as possible. Thank you in advance.