maniix, since you are not encryptblockr, you can't say that his problem is not related to this behavior. Unless you work or live together.
I have noticed this behavior and solved it with this solution when I work on modifying or adding XCP-ng templates. So it is a possibility that has already been tested. But that does not mean that this explanation is always the right one.
In this case we lack information regarding the specific context of encryptblockr. But my answer may be the right one.
In your case, it may be another explanation. And since you don't give much information either...
I have XOAs with several pools on them. Pools of 1, 2, 3, 4 hosts. And it does not display entries for each of the hosts, fortunately!
As I said, when I make changes to templates, I force the scan of these on the XO I am using in order to validate them. The list then shows duplicated entries, and in my case, a reboot of the XO fixes the problem.