Glad to see that you got it to work. The first time I took my FEL off and then tried to put it back on I had the same issue. Apparently when the FEL sits there the hoses build up just enough pressure to keep you from being able to push the lines on sometimes. I found it’s mainly during warmer weather, but have had it happen to me a couple of times during cold weather.
After loosening the connections many times and bleeding it that way I started taking a 3/8" bolt with a smooth bottom, placing it inside the connection with a rag blocking any spray that might come out. And I tap it a couple of times with a hammer. This relieves the pressure and I stopped having to take the connections loose (BIG PAIN IN THE ARS).
Best of luck, Mark