I am using sonic worlds next to make a fan game but this
keeps happening and I'm on mobile

    Can you use the Editor's Profiler? That's the place to start, when you need to improve the performance.

    Otherwise, the only way is to study the code and look for places that need optimizing.

    You can measure how long a segment of code takes:

    var start_time: int = Time.get_ticks_usec()
...
print("Elapsed time (usec) = ", Time.get_ticks_usec() - start_time)

    Raptorkillz is it at least a good phone?
    phones tend to use weird cheap GPUs so they are prone to visual glitches. I had some in among us mobile and the devs response was "update your drives" and I was like "HOW?".

    It could also just be a code problem and not a godot bug, but you are not giving enough information to be able to tell.

        The Mali-G72 MP3 in that device only has 3 graphics cores, so it might be the viewport is too heavy for it at the Fire 10HD's fullHD res. I think there's a setting to halve the viewport rendering dimensions resulting in quarter the resolution for the viewport. That might help with the editor.

        For the exported game you'd have to implement a setting for it yourself.

          Raptorkillz well mobile is not my specialty.
          from just the screenshot, I imagine the bug could be either the GPU skipping cls when redrawing the frame, or you are spawning the same node twice.
          I would check the code first and try to reproduce this bug.
          If it's GPU, try switching from Forward+ to Mobile and then Compatibility. Compatibility "should" work.