Decrease supply confusion

We are 9 months into our bf journey. The last few weeks I have been pumping less at work than normal... 2-4 ounces less (split btw 3 sessions). I am just at a lost on why. I have not changed my pumping schedule at all. Baby still nurses the same as before despite eating solids. Still waking during the night to nurse... lately extra times (sleep regression I think).

I am literally drinking more than my weight in ounces of water a day. I have increased oat intake. Add 5 mins to pumping sessions. Tried power pumping a few times. Made lactation cookies with flax seed, oats and brewers yeast. Same result. I can not get back to what I had been pumping. Is this normal? Is it just something that happens over time? I want to keep going til she is 1 year but this is frustrating. So far I think she is still getting enough but I am worried 😔