Jacuzzi tank when flushing making squeaking noise. Checked inside tank and fill tube popped Out of overflow tube.

Doesn't it have a barbed clip to hold it in the tube or a circular holder to slide the tube through? You must anchor the tube or Newton's 3rd law takes effect-as you have found!

The small white tube supplies water to the bowl. If it is not any overflow tube the flushing action will be reduced. Secure the small tube to the white overflow tube. Good luck, Tom