Regression?

Over the last few months, I’ve felt like I’ve regressed in my progress at OTF, specifically on the treadmill. I’ve had to take my base down to my old pace, my pushes/all outs aren’t as fast, and I generally find the tread blocks mentally tougher and more challenging to get through. This has persisted since early June, so it’s more than just a bad week or two. I’ve been going consistently 3x a week for 3 years. I take a week off here and there when I need a reset or go on vacation.

Plateaus are to be expected, but has anyone experienced this? Not really sure what the cause could be and I’m feeling frustrated. I’m mindful about protein and I’ve never been someone who has to worry about not eating enough (haha). Any advice or just sharing your own experience is appreciated!