I would want to know more about those two horizontal lines to the right. Perhaps they are creating a couple and this bending moment is driving your line up. Chances are, the elbow flexibility (the right end of your lifting line) is overly high - due to insufficient straight run into the tee below. Try a square corner here and see what happens.
Is this a new line? If so, perhaps it will be resting later in life - after shakedown.
Another diagnostic - turn your +Y in the middle of the line to a full Y and see what load magnitude is required to hold it down. It may not be that big. (Again, this support change is not to eliminate the condition but to better-understand what's going on here.)
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Dave Diehl