Hi,
I have a Panasonic 253 breadmaker where the bread looks and smells amazing after I make it.

Recently I made a sandwich loaf which involves a 5 hour bake. However after cooling it basically disintegrated when I was slicing it with a very sharp breadknife.

I then tried with a serrated edge breadknife and the same thing happened – ie the first 2 inches cut fine but then with the movement back and forth of the knife the rest just decided to collapse?
Are there any tips please that any of you breadmaker owners have for improving the consistency of the bread please so allowing it to slice better?

Would an electric carving knife be the solution do you think?

Five hours !!!!
My receipe uses ordinary plain white flour & takes just over 2 hours

I have the same bread maker, the Panasonic 253. I use the rapid white loaf recipe although I usually use half white and half brown flour. It takes just under 2 hours. And I don't choose the lighter crust option. The middle or darker option helps it hold together better. And then cut it with a good bread knife. You do have to go backwards and forwards like mad when cutting and very slowly down. Also don't try to cut it while still hot. And aim for thicker slices than you'd expect. You can't cut thin slices such as you get in ready sliced supermarket bread. If I'm eating a sandwich at home, I'll usually have an open sandwich, so a thicker slice with no lid.

Try the sandwich bread recipe.

I have a similar model. Perfection sometimes takes a bit longer.

OP - are you using strong white flour? Normal flour is not good for breaking bread, there is not enough gluten.