I trained MED1210 to get access to revives, and tested it to make sure I could do it, costing 50 energy. Later I (re)joined a cartel with max revive perks, and now it still costs the full 50 energy. At first, I thought it was due to the 3 day waiting period upon joining the cartel, but I've been a full member for longer than that now and revives still cost 50 energy.

This has been fixed for me now. I checked revives on the hospital page while at below 50 energy several times a day, and now suddenly it is working. 

There was a cartel perk bug that went in and resolved this. Thanks for reporting and apologies for the inconvenience.