I had this issue a few years ago.
The solutions seem to be split into issues with the machinery and issues with the ingredients.
I discounted the mechanical issues as the main one was a dysfunctional paddle, which was OK on my machine.
There are a couple of points of failure with ingredients.
Flour with weak gluten.
Old yeast.
At the time I had my baking issues, there were some UK grown flours that had weak gluten, compared to US and Canada grown crops.
So I bought a different flour and it didn't seem to make much difference.
Then I read two things. The yeast, even though it may be long life and in date, keeps better when refrigerated.
I also read that the bake could be improved by adding a little vinegar or lemon juice. A similar product (Ascorbic acid) is used as a flour improver in commercial bakeries.
At the moment, I have consistently good results using Aldi's own brand of dried yeast (that I keep in the fridge) and Aldi's own brand of strong bread flour, either wholemeal, white or a mix.
I put the yeast in the bottom of the pan, followed by the flour. Then I put the salt, sugar, fat and cold water on top.
Good luck!