YouTube tested 5 unskippable ads for non-premium users instead of 2 ads. 

If you are hesitant to subscribe for YouTube premium to experience ads free content, soon you will probably have to watch five unskippable ads before you can watch the video and this will definitely cause frustration and upset among the users. 

Recently, some YouTube users with free accounts have expressed their annoyance at getting five non-skip ads instead of two before they can watch a video via Twitter and Reddit.

Regarding this issue, YouTube has acknowledged it via Twitter and provided a response stating that the new 5 unskippable ads may occur for some YouTube users with the company’s bumper ads format, which are typically 6 second short-form ads that are unfortunately unskippable.

As of the time of writing, it seems like only some users are experiencing 5 unskippable ads before they can watch a video as it’s not happen to all YouTube users on free accounts. However, it remains unknown whether YouTube will implement the “5-ads format” to all non-premium YouTube users. Additionally, YouTube has asserted that all users are welcome to “Send Feedback” regarding the Company’s ad policy at any time.

Source : [1]