Sour cream peach pecan pie

In addition to the sweetness, marmalade has a pronounced bitter flavor that could overpower the fish. It seems that others feel the same way — there are few online recipes for fish with marmalade, and of those few, most are for salmon which has a more robust taste of its own to balance out the marmalade. Perhaps something like an apricot preserve would be more in the spirit of the original recipe?

I'm looking at the recipe from Karo. The only thing that stands out as potentially being your problem is that the Karo recipe calls for a longer bake time. That recipe gives a final temperature too, 200F (93C). Could it be that your pie is undercooked?