Unfortunately there is still no definite news on the cruise market reopening. Latest information for P & O is November at the earliest, but it could easily be mid-January.
The latest news is that two Italian cruise lines are expected to commence operation shortly but Italian nationals as passengers and visiting Italian ports only.
Vessels that visited Cartagena August 2019:

Jewel of the Seas – 14th August 2019
Royal Caribbean International – 2,501 passengers – 842 crew – 12 passenger decks
Maiden voyage 8th May 2004

AIDA Stella – 11th August 2019
Aida Cruises – 2,700 passengers – 620 crew – 14 decks
Maiden voyage 17th March 2013
Language on board German – gastronomy, schedules, animation geared for the German client

Spirit of Discovery – 8th August 2019
Saga Cruises – London registered – 999 passengers – 523 crew – 10 passenger decks
Maiden voyage 10th July 2019

Britannia – 6th August 2019 – Southampton registered
P & O Cruises – Southampton registered – 3,647 passengers – 1,398 crew – 15 passenger decks
Christened by HM Queen Elizabeth II 10th March 2015
Visited Cartagena this period 3 years previously on 13th August 2017

Thomson Majesty – now Ocean Iris
Owned by Mano Maritime – 1,460 passengers – 620 crew – 9 passenger decks
Maiden voyage 7th July 1992