I tried restarting the services but it already was stuck at 'Stopping' and all other tasks are greyed out. Tried it with PS but no succes. Tried rebooting and still the service got stuck at stopping when the update started running.
I believe it is solved now by setting the startup type to manual of the DA Service, rebooting and then starting the service (and putting the startup type back to automatic). Now OME starts inventory and collections again and so does SupportAssist.
Thank you very much!