I am in the same boat. Just had cover installed yesterday. There is no contact between the cover and tailgate at all so its not holding it back at all. I currently have my negative cable unhooked. I doubt that will fix it.I just had the same issue with my 2019 Big Horn. Installed a Bakflip Fiber Cover and 3 days later my "open tailgate" warning went off. I cannot get the **** thing off for the life of me. I opened and shut it over 50 times, unhooked the negative terminal for 20 min, took my tailgate completely off and reinstalled. I am missing my 2016 Tacoma TRD off-road at this point--0 issues from day one. If anyone has found a fix for this I would be grateful. Thanks!