I can't really describe it, but I have two videos: https://gyazo.com/9ec4845e240128b88d07493145a940c0 and https://gyazo.com/59600c80891679f7a009728bb95695f0.
Sometimes without even jumping, it also happens with trapdoors. Sometimes (however I can't reproduce this one) you can do it without doors, fence gates or trapdoors at all.
Check out MC-152824, it's exactly what you've shown here.