Shape shifting object that shimmered and or produced white yellow lights in different spots.

Object flying at high altitude, about as high as airliner, was seen by 4 witnesses flying or floating over Houston County, GA from 1838 (approx. overhead) to 1855 (when it could no longer be seen on horizon).  Seen on 5/14/2021.  Object traveled in a southeast bound trajectory.  Object seemed to shift change, flash lights, and or shimmer irregularly.  Shimmer or lights were silver, white, or yellow.  Object was moving much slower than an aircraft, did not emitt any detectable sound.  I took video of object, sketched at time of viewing, and took notes.  Object may be high altitude silver balloon, or ballon group, however object seemed to be too high to be ordinary party balloons. An aircraft was seen in the vicinity of balloon at approximate altitude as baloon. My estimate is that it must have been at well over 18Kft.