For some reason, whenever I use the /tp command, I teleport 1 block over on the positive X axis. For example, if I did "/tp -181 58 101", I would end up at the coordinates -180 58 101. I don't know if it's a problem with my computer, or the save file, but if it's either of those, or anything else, can anyone tell me what's happening?
This is actually completely normal. If you run the command
/tp -181 58 101, you will not get teleported to those exact coordinates. If you look at the decimals, you will notice you got teleported to
-180.5 58 101.5. That's because you get automatically teleported to the middle of a block, so the game finds the closest middle point of a block, which is why you are half a block off if you teleport to negative coordinates (it works on the Z axis too). It's simply because -181 rounds to -180.5 rather than -181.5.
If you need exact coordinates, type in your decimal places:
/tp -181.0 58 101.0
Like this, however, you will get teleported in between 4 blocks. If you want to get teleported to the middle of that block simply put .5 in the decimal place, like so:
/tp -181.5 58 101.5