Windshield Washer Fluid Leak that Fixed Itself?!

[Tomato]

2023 Sierra 1500. Very strange. Had my truck in for service (just oil change & tire rotation), took it through my local carwash, then parked it for a week. Pulled out of the garage and found 75% of my washer fluid on the floor. Checked and could not locate a leak or wet area. Applied positive pressure to the fluid reservoir and it held. Refilled it a week ago and no leaks! I haven't used it much, but the pump seems to be fine as well.

 

What the heck could have caused this? I'd suggest some dip at the dealer poured it all over the place under the hood, but the low fluid warning came on when I first discovered this, and I found no evidence of that.