LX470 AHC making popping/balloon rubbing sound

[Toyota47L]

My LX470 AHC still works in that it will lower, and lift in both H,L mode, when I got the car the oil reservoir was very low. I refilled this morning and ran it through the different settings. I notice that when it's in L it does take a while to go back to N but raising and lowering seem normal. When it drops back down to N it also does it relatively quick. What is worrisome is when it is in N now it's making a continuous popping/ air sound as if someone is trying to pump a bicycle with a hand pump and there's little popping sounds, it is most prevalent right in fornt where the driver's side is but every now and then that sound emanates and comes from the rear left and right as well as passenger front. I know the AHC is a connected system. Has anyone had this issue with this symptom of having this noise? I'm hoping it's bubbles in the system when I introduced new oil to the reservoir earlier that's causing this. I intend on bleeding the system when I get another can of fluids since my dealer only had one in stock and I didn't want to not have enough to refill since the reservoir was so low when it was in the N setting.