I've encountered this issue where I have two actions in a rig moving an image, they somehow overlap and break each other.
I cannot explain it well, but here is a video showing the problem: https://youtu.be/R1erHuD68hs
I basically have this rig, and in one action, I move this image left/right, and in another, I move it up and down, when I move the image left/right with the bone rig, it works fine, but if I try to continue this independently with the other bone going up and down, it somehow goes left/right as well and breaks the rig.
I noticed that if I do the up/down first, and then left/right after, the up/down is fine, but the left/right is affected now, which makes compels me to believe that I messed up rigging the bones somehow.
Yeah, creating a conflict is easy when two Smart Bones control the same item. Fortunately, there are several ways to solve this problem.
The way I typically approach this is to separate the conflicting transforms to different items. For example, if one Smart Bone is animating the X and Y transforms of a bone, I'll place the art layer in a parent group and have the second Smart Bone control the X and Y motions for the group. Tip: Be sure to position the group's origin to where the bone is.
This is just one possible variation of this technique. Alternatively, the second bone might control the X and Y transformation of the art layer directly, or it might control the X and Y movements via point animation. The idea is to assign the x and y motions to different items so the Smart Bones aren't fighting over the same item. This approach is really easy to do, and it works for me most of the time.
The exception might be when both Smart Bones must animate the points directly. That's when I turn to the next solution:
The Mixed Smart Bones technique solves conflicts by adding a third Smart Bone to correct the bad displacment. This method is explained in this video by KuzKuz:
Be sure to hide or Shy the corrective Smart Bone because you don't want to accidentally animate it on the Timeline.
BTW, you can automate this process by using this script:
But before using the script, I highly recommend learning how to do this manually first. This way, if there is a situation where the script fails, or you need to change the script's result, you will know what to do about it.