Does Clickbank shave international affiliates ?

I seriously doubt that ClickBank is doing anything to shave your sales results.

I could be wrong, but it sounds like you are under the impression that your sales results, or the results for any given product(s) can be expected to remain constant... with no additional effort on your part.

If that's what you think, I'm sorry to disappoint.

You've told us nothing about how you get traffic to your offers, but...
1. If you have multiple traffic sources, your mix of traffic from the various sources may have changed even though you're still seeing the same aggregate number of visitors.

2. If you have a single traffic source, the quality of that traffic can easily decline... even if you are receiving the same number of visitors.

3. Even if you get the same level of activity on your affiliate links, the product(s) you're promoting may be slowly falling out of favor. New competitive products may have been introduced that are attracting attention (and your buyers). While you may still be getting the same number of clicks - the visitor just looked at a) a newer competing product, b) a more desirable product, c) or a cheaper offer on a competing product.

The point is that you cannot assume that x number of clicks = $x over time.

You need to constantly look for new ways to promote your merchants offers, look for alternative products that you could be promoting, etc. Affiliate marketing is NOT a passive activity.