Perplexica not receiving SearXNG results

On Umbrel with umbrelOS 1.5, I installed both SearXNG and Perplexica from the App Store.

I added the SearXNG URL in the Perplexica / Search config section:

http://myIP:8182

Unfortunately, Perplexica does not receive search results.

Checking SearXNG setup from command line:

curl -X GET "http://myIP:8182/search?q=test&format=json"

returns the information:

Found. Redirecting to http://myIP:2000/?origin=host&app=searxng&path=%2Fsearch%3Fq%3Dtest%26format%3Djson

Any idea where this redirect 8182 to 2000 derives from, and how to avoid it?

When I used SearXNG previously (not on Umbrel but might be similar), I had to add the json format in the settings.yml.