Used the Plaza lounge at LHR T2 today with my UK Amex platinum

Was told by the agent that my visit is limited to maximum 3 hours and I have to pay an additional fee if I wanted to stay longer. It didn't matter today for me as my flight was in 2 hours

Has anyone else had a similar experience recently .. So far with the priority pass select which I have with my Amex platinum or with the Amex platinum directly I've never been told about a stay limit in the 10 + lounges I've used this month .

PS: for those who are not aware Plaza lounges in the UK have ended their contract with priority pass / loungebuddy etc. However those with Amex platinum and above can get entry..