Setup:
Using WDQS:2 (wdqs0.3.142 from Oct 28, 2024) which solve correctly the issue to set the WIKIBASE_CONCEPT_URI required in wdqs-updater container (Note: However fix is needed in docker-compose.xml to set the correct version here)

Issue:
The PREFIX in SPARQL query is not using the correct concept URI in wdqs container.
Indeed, setting the log "com.bigdata.rdf.sail.webapp.BigdataRDFContext" to level "debug", messages show:
PREFIX wdt: http://wikibase/prop/direct/
PREFIX wd: http://wikibase/entity/

instead of something like:

PREFIX wdt: https://concept_uri/prop/direct/
PREFIX wd: https://concept_uri/entity/

Recreation:
Any SPARQL query using prefix like wd or wdt from wdqs-fontend container UI.
For example this query doesn't return anything:
select *
where
{
?s ?p wd:Q1
}
LIMIT 10

whereas this query return the expected result:
select *
where
{
?s ?p https://concept_uri/entity/Q1
}
LIMIT 10