Reports Builder 12.2.1.3.0 - how to force display of repeating frame based on empty query

hi,

I built a repeating frame based on a given query (eg: list of invoices and resulting subtotal). This query may returns an empty set, which would cause the repeating frame not to be displayed.

I am trying to force my RF to be displayed even on a empty result set, but I could not get it. Someone suggest to place a formula field into the query group RF is bound to; then place a summary field (external to the query group) counting the items contained in query group, and finally force the RF to be displayed if this summary is 0. I tried it unsuccessfully.