Try a little bit of cornflour slurry to try and thicken it.
I add frozen green beans to mine, as cheaper & handier than fresh, and constantly forget to cook them outside of the curry and add before serving.
Inevitably I chuck it all in the put then scratch my lead wondering why it’s so runny
I keep a sneaky block of coconut cream in my fridge, it’s good for thickening too.
If you have enough for leftovers highly recommend popping a few noodle nests into the curry saucepan when it’s hot, remove from heat and put the lid on to it all cools down.
Cooks noodles taking up all that scrumptious sauce as they cook.
Delicious ready to microwave pad Thai for the next day.