Lou,
I am experiencing the same problem with my 2015 edge. I took it to the dealer, asking them to run a diagnostic check. They kept it overnight w/o running the diagnostic and informed me that I needed to take it a body collision shop as it appears to have been in a collision. To my knowledge that is not true, I purchased it used. However, I took it to a body shop, the owner looked at and on this particular day the liftgate decided to work properly. He stated he did not see any signs of a collision or misalignment. To figure it out it would be like exploratory surgery, at that point I only saw dollar signs. I ordered replacement power liftgate arms. Installed them. They worked for all of 5 minutes and we are back to the liftgate doing a one shoulder shrug of trying to open without success.
Made sure it relatched because I’ve experienced the battery drain and has since purchased a new battery.
Since the replacement did not work, I’m back to searching for an answer like you.
Does anyone have any suggestions or ideas?