I have this query that used to work until recently, and it didn't take more than a second. I have just under 300 relationships in my graph, and the intermediate results at most reach 1k.

prefix : <http://turis-ucuenca/>
prefix org: <http://www.w3.org/TR/vocab-org/>
prefix myorg: <http://turis-ucuenca/org/>
prefix myregiones: <http://turis-ucuenca/region/>
prefix lugar: <http://turis-ucuenca/lugar/>
prefix myusers: <http://turis-ucuenca/user/>
prefix foaf: <http://xmlns.com/foaf/0.1/>
prefix tp: <http://tour-pedia.org/download/tp.owl>
prefix vcard: <http://www.w3.org/2006/vcard/ns#>
prefix geo: <http://www.opengis.net/ont/geosparql#>
prefix dc: <http://purl.org/dc/elements/1.1/>
prefix fb:<http://turis-ucuenca#>
prefix base2:<http://turis-ucuenca#>
prefix unit: <http://qudt.org/vocab/unit#>
prefix geof: <http://www.opengis.net/def/function/geosparql/>
base  <http://turis-ucuenca/>

select ?creator ?creatorName  ?place ?creatorImage ?placeName ?placeCategory ?placeStatus 
?placeDescription ?placeDate ?placePoint  ?imagesFbNode   ?region ?regionName ?org 
 ?orgName ?favorite ?distance  WHERE {
        ?place a tp:POI.
        ?place base2:status ?placeStatus.
        ?place dc:date ?placeDate.
        ?place base2:facebookId ?imagesFbNode.
        ?place dc:title ?placeName.
        ?place dc:description ?placeDescription.
        ?place geo:hasGeometry ?geom.
        ?place base2:category ?placeCategory.
        ?geom geo:asWKT ?placePoint.        
        ?region a :Region.
        ?region dc:title ?regionName.
        ?region geo:hasGeometry ?geoRegion.
        ?geoRegion geo:asWKT ?regionWKT .
        ?org a org:Organization.
        ?org dc:title ?orgName.
        ?creator a foaf:Person.
        ?creator foaf:name ?creatorName.
        ?creador foaf:depiction ?creatorImage.  
    ?place dc:creator ?creador.
    ?region :isAdminBy ?org.

We need to investigate what is happening on your Stardog Cloud instance. Please let me know the name of the instance where you are having the problem.