Why does my bread dough sink?

[MavisGrind]

Have been making my own bread now for some time however recently it's started sinking once I've put it in the oven.

It rises nicely in the bread tin but once baking it sinks. Any ideas?

I've tried varying the oven temp and I've recently switched to a silicon 'tin' - is that the problem?

TIA

hmmmm, it could well be the tin.
they're fine for cakes and things, but proper breasd tins tend to be thick, heavy things. thicker than a metal cake tin even.
because they need the additional heat I think.

try again with a metal tin, and if it comes out ok you'll know it was that