There are no, and never were, issues with clickbank.
However, some people think that they can have a go at it for 30 minutes, maybe buy a couple of fiverr gig, and expect to get rich. When this does not happen, rather than acknowledge that they did not put in the work, they say the system is 'broken'...it is much easier to point fingers than acknowledge one's mistakes, shortcomings, and limitations.
In the meantime, all the others who are putting in the work and keep going despite failures and setbacks, are seeing sales pile in on their accounts, and continue doing so quietly with a smirk knowing that all the complaints and whining mean less competition for them.
Have a good look on all parts of the forum and you'll notice one thing - most thread are saying that method XYZ is dead. The clickbank section - clickbank no longer works...SEO section? - SEO is dead...bing ads section? bing ads is dead....facebook ads? they no longer work...youtube section? you can no longer rank and it is dead too...negativity is all over...people come to this forum thinking that IM is a 'get rich quick' push button thing, and then complain when they realize it is not...
Well guess what? I've been around the forum since 2012 and from my first day here I remember seeing threads popping up all the time saying you can no longer make money online...since then I've personally worked with tens of completely IM newbies who were not discouraged from all the negativity and were willing to put in the work...these newbies are now making more per day than most people will ever make per month on their 9 to 5, and several have quit their jobs altogether. You won't see these people posting much here though because 1. they are busy making money, and 2. successful people tend not to brag because they don't need to massage their ego.
So really it is up to you. You can justify giving up before even getting started by saying that clickbank is no longer reliable, or you can roll up your sleeves, get ready for some longgg nights of keyboard bashing, and get busy. 97% of people reading this will opt for the former, because laziness is a dominant human trait and we are extremely skilled at finding reasons to justify it. For the other 3% though, IM will change their life and in 12 months time they'll be making more money than they'll know what to do with it.
The choice is yours.
Mancar