Sometimes I am reversing my car out n the roller door closes. Thankfully one of kids run over to door n stop it by pushing up against the door so it goes up.

Personally i would call the seller and have them look at it. It is not a great concern, sounds like vibration.

It sounds like the lid is warped or bent sometimes by putting basket on top or laundry detergent. Also sometimes kids sit ontop

Deb, that reversal is a child safety device - if the bottom edge of the door detects contact with any object, it'll immediately reverse so it doesn't kill a child. Or a cat, dog, whatever.

The opener mechanism should have a stop switch that prevents the door from closing hard against the floor - that stop switch needs to be adjusted so that the door will stop JUST before hard contact. That'll take care of it "bouncing" off the floor & reversing. As to it reversing before it touches the floor... examine both guide rails closely to see if there's any obstruction that the door's bottom edge may be contacting to trigger the child protection reversal switch.

Look for little button or pin that pushes in at door frame when door is closed against it . Sometimes metal, sometimes plastic (black) . If it is faulty, it will cause that.

Try cleaning the door tracks and rollers as if they are sticking the motor will reverse as a safety function. Use WD40 and wipe clean then apply some spray grease.

Garage door work like a wedge. As it goes down the door get closer to the jam. So if you moove the weather stips closer to the door that probebly solve your problem. Do that whith the door complitely close.

Good day Paul

There is A Spring or Spring type Mechanism At the Door that POPS the Door Open Once the Button has been Pushed . And when you Close the Door This Same SPRING ACTION Sorta Fights Against your Closing it. Well it Sounds to me as if this Spring Action is Not Working Properly,
Take a CLOSE Look at this and Be sure This is Working Properly, My References Do NOT Go into DETAIL on this so its Kinda a Common Sense Approach to it.

U will need to buy a can of spray white grease and clean and then lubricate all the tracks the door channels on as well as all the latches for the door, this will cure the issue in most cases, did allot of these while working at a Ford dealer.

Pick up the printer, lay it on its front and close the reg cover. Simple as that but it took me ages to figure it out!!!!