Custom depth overlapping each other

hi everybody here.
i have a custom highlight (altered survivor vision from marketplace ) function using custom depth and i use the marketplace asset waterstamps, for waterdecals on transparent objects.
the waterstamps look fine, but they are overlapping the highlight function of my interactive objects.
i have no idea to stop this behaviour. i tried setting them to different custom depth layers, but they still overlap.

Does anybody have an idea ?
kind regards
stucki