slight imprecision ROTATING/SCALING (random numbers after comma)

hello everyone!

when i try to rotate any object in unreal editor 4.17.1 with GRID SNAP VALUE turned ON, i often get random numbers a few digits beyond comma that do not belong there (image below, red arrow). these imprecisions even remain when i rotate the object back to 0 (step 4 in the image). it also happens when moving or scaling objects. this is really annoying because i have to go through all the values later manually and double check all the assets. how is this even possible and how to correct it? i expect mathematical perfection from a computer program.
please help me! thanks in advance.