Using more than one element on a page takes the data sources from the first element
For e.g. if you create a grid element and connect to Civi Contacts, then add another grid below that connected to the same source, no matter how you define the contact sources in the second element (filtering on group/type/field/etc), it uses the values from the first grid (including filter, sort order, etc) and shows the same results.
This is the same for both Civi Events and Contact entities, but if you use different entities (ie contacts in first grid and events in second) both will load.