Windshield wiper fluid tank spout issue

Not sure why this is happening, but sometimes when I add in wiper fluid, the intake spout part of the wiper fluid tank seems to fill up with fluid, even though I'm pretty sure the tank itself is not full (you can even see in the picture the top part of the tank is unfilled):
https://photos.app.goo.gl/dY81UTEVE6K5KSWx5

I've detached the spout before, and there was no obstruction (all that fluid contained in the spout part just spills out when I detach it.) It probably isn't due to the fluid unable to flow down to replace/displace the air in the tank either.

Anyone else have this issue?

interesting. All I can think of is some type of an obstruction on the tank itself if there is none on the spout. I've seen washer fluid freeze before that caused blockage.

It looks like the air can't escape the tank. Maybe try pouring more slowly. Is the car level when you fill it?

Yes, car is level. I'll try pouring slower.