Background HDRI overlaying on render? WHY!?

so ive been having this issue where every like 10 or something frames the image gets darker, ive been trying to figure it out with no fixes, but in my later frames i descovered that the HDRI is overlaying over the rest of the image, does anyone know why this might be happening? it seems super random and buggy… if anyone has a fix for this or a lead on what might be happening please let me know…

Try to render your background as separate layer and recombine it in the compositor.