Excuse me, but I don't speak English so I have to use a translator.
I use their mods:
"Deadlock's Stacking Beltboxes & Compact Loaders"
"Deadlock Stacking for Vanilla"
Today I installed "Deadlock Stacked Recipes" and the required "Factorio Standard Library".
When I loaded my last game, I noticed that "LTN" was no longer generating any orders.
I removed "Deadlock Stacked Recipes" and accidentally left "Factorio Standard Library" and "LTN still didn't work. Only when I removed" Factorio Standard Library "did" LTN "work again.
Conclusion: "Factorio Standard Library" causes the error, but without this mod your "Deadlock Stacked Recipes" does not work and crashes.
Maybe they can do something about that.
Many thanks in advance. Good mods.

Can you please supply a save file so I can sync your mods

I don't use LTN as I prefer TSM, so its not something I have come across before.

Hello, I saved 2 games for testing.
The score "TestDeadohne" is without your mod "Deadlock Stacked Recipes" and the mod "stdlib" and works.
The score "TestDeadmit" is with your mod and the required "stdlib". No changes were made except that the smelting furnaces received the stacked iron ores directly. And no further orders with LTN are generated here.
If you then load "TestDeadohne" again and remove the two mods, it works again. In my opinion it is not your mod that leads to this error, but the "stdlib", without which your mod "Deadlock Stacked Recipes" does not work.
https://we.tl/t-0d9exmEwWN

I removed the stack limits on the combinators and it worked
I set the requester station to request -1500 stacked iron ore and the train turned up
https://we.tl/t-6iioYBLb6a

Please note that DSR overrides the stack size of the ores so that you get 50 stacked iron ore per cell.