Coolant fan issue

Took my 2017 Scout for its longest ever one day drive today, driving pretty much the full length of France whilst towing a caravan. All up weight of car + caravan was 3500kg. The old girl was working hard.

Realised just how hard towards the last hour of the 12 hr epic, when the air con cut out due to engine temp getting too high. Gauge on the dash indicating 115-120c.

I have an OBDeleven reader so did a quick scan to see what was going on and had a P195000 code “coolant fan for coolant - difficulty of movement/blocked”.

The live data showed the fan sitting at 10%. I slowed down and the temp reduced. Eventually the fan seemed to come back to life and I could see the speed increasing and decreasing under load.

Any ideas what might be going on and what I need to look for? In France for two weeks so can’t afford for the car to overheat!