YouTube are accepting my monetisation requests again?

I have had monetisation on my YouTube videos for around one year now, and I used to have no problem getting adverts next to my videos, mainly due to the fact that I own the rights to everything that I upload to my channel (with a few exceptions with soundtracks I use). For around half a year now, YouTube have not been accepting any of my monetisation requests on my videos, and the ones that weren't getting declined just sat there saying 'under review', until I cancelled monetisation on that video. It was getting very frustrating, and I was losing all of the motivation that I had gained to uploading my original content and cinematography videos onto my media channel 'RedSpectrumPictures'.

Well good news! I was randomly trying to monetise a video today that I have had uploaded for a few weeks, and I checked my 'Video Manager' and amazingly YouTube had accepted the request straight away, and it had adverts next to that video. I then decided to request monetisation on all of my videos that had been declined or under review in the past, and again YouTube accepted them for monetisation. I really don't understand what went wrong, I have looked on forums and on Google and have found others had this problem. I just thought I would share my story, so others can also see they are not alone with this. I had a feeling this may have had something to do with YouTube allowing monetisation on any account?

Just as an example, I have embedded one of the videos that they accepted earlier today. It is also a video I haven't shared on my blog before, it is a rack focus test on the Canon 50mm F/1.8 II prime lens.