Can’t figure out what bird this is and it’s driving me crazy(Austin, TX)

I was out around my house when I heard a very distinctive bird call. It was soft and clear. It was a hee sound, possibly a bee or tee or any similar ee sound. It sounded almost haunting. It repeated this note 8 time with zero variation. It was kind of monotonous. I didn’t have my phone so I couldn’t merlin it and by the time I could it was gone. Each note was about 1/2-3/4 of a second long. There was no space between the notes, so it was heeheeheeheehee, not hee hee hee. I’m not sure if this makes any sense. I cannot figure out what bird this is and it is driving me up a wall. I have checked, and no, it is not a chickadee

TL;DR: Soft, haunting, ”ee” like sound that repeated 8 times with 0 variation in the notes