I get three alarms when only one should be triggered. In the screenshots below you can see 3 disk alarms. warn, minor and major. All of them triggered because of 81% usage. But only the warn threshold should trigger in this case.

I've attached also the disk and threshold definitions.
Also the Mattermost discussion about this issue: https://chat.opennms.com/opennms/pl/zprs57xto3bc7yatkurufjmh9r