The whole thing is quite strange.
I used a default grid with only the pagination enabled and it just did not want to work.
On the client side the pagination worked as it should (display of pages, results per page, etc.) on the server side the dm.Take and dm.Skip properties were always the default values.
However, when I tried again today, without changing any single line of code, it all worked correctly...
Thus the issue has resolved itself.
I am truly grateful for your help, at a complete loss as to why it works now and sorry for the inconvenience.