Ice keeps forming on the bottom of the freezer - like a leak on the back side flows into the bottom toward the door.

Something here should cover your problem.
side by side refrigerator ice on freezer floor YouTube

Try removing the strap holding the drain hose underneath that drains into the pan. Otherwise it acts like a p-trap and holds water that then insulates the upper part of the tube. Condensate water eventually freezes high up in the tube and backs up everything pushing the condensate water into the bottom of the freezer where it freezes into sheets. Leaving the drain hose down keeps air in the tube all the way back up into the freezer area. This seems to keep the condensate water flowing freely into the bottom pan. The air in the open condensate tube does not seem to have an ill affects. Also, you can add some stranded bare copper wire around the heating element just above the drain tube inlet and then push the tail off the copper wire down into the drain tube hole. This helps keep any water in liquid form flowing down the drain pipe.

drain is plugged up were it is normally drain to defrost the freezer completely find a place to store food in freezer for a few ours leave door of freezer open pull out all shelfs and lay a few tools down at bottom of freezer were you seen the ice build up after you have done that pull ref away from wall take back of bottom look fro drain pan with a turkey baster send water thru back of freezer inside if water still flows back out into freezer drain tube is still clogged use warm water when doing this if you see drain pan full of water use a shop vac that can deal with water suck out water send water again water should go strait to drain pan if still flows out may have to remove drain tube

If there is frost forming at the bottom to the door, your door gasket is leaking at that location. You may be able to relax gasket back in place with hair dryer, be carefull you can melt gasket. If it is sheets of ice, your defrost drain may be frozen

If we have ice on the inside of the freezer it means air is being pulled into the box somewhere. The most likely place is the door seal, it sounds like you already checked it, but I would suggest that you look very close at the bottom and aides of the seal too, it could be leaking in air from there. Check the inside liner for cracks and seal them if you find any. Look at the corners of the cabinet to make sure there is not room for air to come in.

Air leaks will lead to frost, it is just hard sometimes to find where it is leaking in.

The doors should be warm. There or heaters in the doors or what they call a yodelers loop in the frame around the doors that keeps condensation from forming. Make sure the fan if blowing on the compressor and the fan inside the freezer is also running. If so be sure there is no ice built up on the bottom inside back panel of the freezer. If so you will have a defrost problem and the coil is full of ice and not allowing the air to flow through it and cool the fridge. If there is ice, the heater behind the panel is most likely bad.

Self-defrosting refrigerators/freezers dispose of the water generated during the defrost cycle, usually via a tube or channel that directs the water to a pan at the bottom of the refrigerator. From the pan, the water normally evaporates.

If the tube or channel is clogged or obstructed, the water backs up and leaks into the inside of the refrigerator/freezer compartment. Then the water builds up at the bottom, inside of the refrigerator. When the water has built up for a time it may spill out of the front of the door opening. To fix this problem, clear the drain tube or channel and allow the defrost water to flow down to the drain pan.

Hi sckk,
ngafm at your service,

Your indoor ice and water keeps getting iced up.
There is an air leak somewhere between the ice and water dispenser on the door and the freezer!
there are many places that this may be. But usually the spring loaded door where the ice drops out to the door ice machine!
It takes a good tech sometimes a couple visits changing a couple of parts till he gets it.
There is no sure fire way to diagnose which part is the culprit thats leaking air.You need an experienced tech that eyeballs it and knows what parts to choose first to be replaced.
The air leak almost microscopic to the eye.
Sometimes you take ice from the door and the crack only closes full some time after wards. Then the tech comes the next day and sees nothing. Or it is intermittent problem!

My advice is only a trained tech can remedy this problem, this time!
If I were there I'm sure I could nail it down!

You need hands on service!
Bless You ,
ngafm,
please give me a goo rating before you sign off.
Thank you.

probably the defrost drain blocked. remove back panel from inside freezer and melt ice off with hairdryer and follow up with hot water till water flows away freely.
you may find all the pipework iced up and if so you have a problem with defrost system.
an alternative way is to switch off for 24 hours and leave doors open

Defrost drain system is plugged and not draining out the back and into the drain collector. There is normally an air trap in this drain line under the back and behind a fiber removable panel. Check this trap and make sure it is clear of any blockage. You will then have to defrost the freezer and clear out the ice. Don't forget to replace the back fiber panel.