Hi! I have a freestanding bathtub that doesn't drain unless you pick up one end first and set down. So tub is filled with water, tub drain open, no water leaves. Pick up end of tub, set back down, water starts to drain. Any ideas what I might be doing wrong with the plumbing pipe connections to cause this?

You must be very strong.
I think it would be easier for the plumbers here if you described or posted a picture of how you plumbed it, especially at what distance below the floor the trap starts.

Are you saying that if you raise the foot of the tub, the water will drain while you hold it up? Or are you saying that if you raise the foot and then set it back down the water will start draining?
What kind of drain stopper do you have?

Is it a recent installation ?

Free-standing tubs are tricky to plumb. Since you have to pick up tub to get it to drain, it makes me think that the drain may not been not installed properly.

Also, as mentioned above, it is very possible, the drain stopper is somehow plugging the drain inhibiting drainage in the process

Please, describe your tub / drain situation in more detail. Also, if you can post few photos, that would helps us to determine the cause of the slow drainage as well

Back to you

Milo