Manually activated forwarding to external number for a call queue not working

[hostcake-it]

A client has one 3CX instance which covers three trading locations. Each location has an 'Office Open call queue and an 'Office Closed' call queue (for days where they are not open it sends calls to an extension at a location that is open).

One of these locations the Office closed queue is still working fine and forwarding calls to another location extension. However yesterday this customer had a staff member call in sick and needed that location set to forward even though it was an Office Open day normally. I told them to logon the webclient for the extension at the closed location and 'login to queue' and also set the external forwarding to the extension of the other location that was open.

However calls still got answered by the call queue and were not forwarded. There is only one agent in that call queue which was the one that had external forwarding enabled.

Does setting external forwarding on a queue agent not work manually?

Or does having the existing 'Office Open" queue set to the Office Hours override the ability to do this external forwarding?

Maybe this is by design but, if so, is there some other method the customer can use to adhoc set forwarding?

Appreciate any advice about this!