Steps to reproduce:

1. Add calculated item with

trendcount(//vfs.fs.size[/,used], 1h:now/h)

1. Click on Test.

Result:

trendcount() returns more than 1, or, in case of an item with 5m-interval a 12.

Expected:

According to the documentation, however, it should be a 1 because only trend values may be counted.

This is also a problem because it is not possible to check how many trend values are actually present in the time period if the total number is influenced by the number of history values.