Ardour (and Audacity) can't detect effects from guitarix and rakarrack

Ardour and Audacity on my computer are able to detect sound coming from digital amps like guitarix and rakarrack but they can’t detect the actual effects coming from these apps. I am connecting them using Jack. I see the bars moving and I have connected everything okay in rackarack. I can hear the effects when I play, but when I record I only hear the guitar without effects. I have the same issue as the user on this forum:
I am using Ubuntu.

I would like to echo one of the replies at the Ubuntu forums:

“Maybe a good start is open qjackctl (or patchage, whichever you prefer) and disconnect all. Once you have disconnected everything in Jack, you should hear absolutely nothing when you play or attempt to record guitar.”

Or could you perhaps upload a screenshot of your JACK connections?

JACK should not be needed at all. Do you have the plugin versions installed? sudo apt-get install guitarix-lv2?

You can list installed guitarix plugins as follows

lv2ls | grep guitarix

Does that show ~70 lines of plugin URIDs?