I was doing some testing with Tide, Stardew Fishing, and the Fishing Real mod, and I found out that when you collect a Stardew Fishing treasure box, only the fish entity was pulled after the minigame and not the loot items you would get from the treasure. I thought it was because of Tide at first, but after trying it with just Stardew Fishing and Fishing Real, I saw that no treasure was pulled even with Tide disabled.

I will look into it.

This is actually an issue with Fishing Real itself. This line cancels the ItemFishedEvent if any of the drops spawn an entity and ignores any that don't.

Oh, interesting. It might be worth bugging the fishing real devs about that; it looks like they ignore pulling any extra items that don’t correspond to an entity, when they should be pulling those items anyway along with the fish entity.