Bread

@Silly_Savage
I've found as my house has gotten colder recently the dough is "tighter" when working it. It doesn't stretch as easily and kneading is harder. Keeping the dough a bit warmer (I put it the bowl by the radiator or fire while it rests) helps loosen it and let it relax more.

In the pic up there the bubbles are bigger toward the top of the loaf, so possibly under proofed resulting in the steam blowing bubbles up as you bake (the lower bubbles having more weight on them and not inflating like the higher ones). But also possibly over proofed as TvH says with the weight of the dough collapsing the smaller bubbles.

Your starter will go through cycles as the balance of microorganisms (yeasts/bacteria) adjusts. Sometimes you will get a real tangy smell (from the lactoc acid bacteria), sometimes it's more yeast-y (from the yeast obviously). The texture can vary a lot as well. Sometimes I get a really strong gluten structure developing in my starter and others it's just slop.
Generally neglecting a starter a bit will see the yeasts start to die off/go dormant and the lactic acid bacteria take over a bit so you could try that with a bit of your starter if you wanted a tangy "shot" to add (never tried this myself but I keep a rye starter and a wheat starter and often use a mix of the rye which is much more tangy smelling and the wheat which is generally more balanced - 50g rye and 150g wheat to 400g flour).