My client enabled document integration on entity serviceactivity. When opening entity things look like this (Slovenian language, but it looks the same in English):

Please note missing icons in navigation and ribbon (just for documents).
Some of buttons work (Edit, New, Upload,...). I'm having an issue with "Delete" button which doesn't work?
Debugging client script i noticed that function
Mscrm.CommandBarActions.deleteSharePointRecords
is looking for a grid:
var $v_0 = window.document.getElementById("associatedGridRibbon")
which can't be found: $v_0 ends up beeing null
I can open sharepoint location and delete document from there. Document integration is working normally on other (new) forms. Environment: CRM Online & SharePoint Online
Any insight into this problem would be very much appreciated.