Erl high cpu usage

I’m using Community Edition 5.1.1 build 5723 on Windows 10 and recently noticed a high cpu (and memory) usage by erl processes.
now it’s just choking my pc, usage get sometimes to 60%, while most of the time is 15%-20% constantly and doesn’t drop below that.

I haven’t added any new buckets/documents/indexes recently.

How can I find the cause and fix it?