Running version: 1.35.6~20200925160318-bionic
If you start a recordering manually on a nodect (may happened with other monitor configuartions too) Monitor and have set section length for example to 10 minutes.
The first event will get a propper cause for example Forced Web or the one you set manually.
But after the 10 minutes are over the next event get cause Unknown doesnt matter if the cause was set manually or if its Forced Web