Possible Bearing Issues?

[[R47]]

I think I have a bearing that's going on my 130x. The last couple of times that I landed, the rotor revved down pretty quick. After the landing, I enable throttle hold, and I had to push quite forcefully to get the main rotor to spin. Also, before the flight there was a faint speaking sound when I spun the rotor, but I couldn't identify the source. Once I unplugged the battery, the rotor was still difficult to spin, but after wiggling it back and forth a couple times once I was back inside, it spun like normal with no squeaking. I'd also like to note that the rotor sounds like it revs down at random times while in any flight mode. Could this problem (bearings or whatever they are) be causing the rotor to slow down mid flight? Also, why does this issue go away at random times? And it almost always happens when the rotor spools down. Sorry if this post is confusing, and thanks for taking the time to read it. And help is appreciated. Thanks