2015 F-150 Sport 4x4 model.
Son ran over a basketball pole that was not cut quite close enough to the ground. It was about 8" high and he cracked ground shield on front. But when he backed up, the plastic did not give the bumper did. Now, would have thought the plastic would have just broken off. Pulled both sides of the bumper down about 20 degrees. Taking it to dealer tomorrow to see if this is a problem with the bumper. Anyone seen anything like this?

 

What you describe is similar to a situation one of our customers trucks encountered when hitting a road sign, rolled over it forward with minimal damage but the spring like action of the steel pole the sign was mounted on acted like a fish hook as it sprang up when it encountered a void space behind the bumper.
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The 'bumpers' on these trucks are very thin and don't do a whole lot in an accident. When I swapped mine, both front and rear, I was surprised to see how flimsy they are. Unfortunately I think your dealer will tell you that's just the way they are made. I would start looking on eBay for a replacement- I'm sure the dealer price will be at least twice as much.

 

My dad just had his front 2015 bumper replaced from a fender bender. Dealer charged insurance $600 for it. Plus labor.

eBay specials can be had for half that.