You tried all the easy stuff, now it's time to try the more obscure.. people have been surprised that their problems were related to the POE adapter.. you might be too, but at any rate, it's probably the best next thing to try.
No need, I can guarantee if you use the included power supply (or any other regular 1A+ type A supply) it will solve the inclusion problem.
There is a reason I jumped straight to that thought, have seen this many many times in the past. Always the same issue, and almost always the same solution.
Thank you everyone for your support. I replaced the POE splitter and installed a receptacle inside the electrical housing box with the supplied power cable for the hub. Everything was successfully added in and now works without any delay. Before some switches would turn on only and I couldn't figure out why. Thank you all again!
“Now you know, and knowing is half the battle”
Glad you got it figured out. It probably doesn't matter much in your scenario, but for best range laterally you want the antennas pointed up and down/vertically.