Given that she's been guzzling down water like there's no tomorrow and the soil's drying out super quick, it could be a watering issue. Maybe she's not getting enough water, or perhaps you're overwatering her.
But considering you're noticing good new growth after watering, it might not be a water problem after all. It's possible it could be a nutrient deficiency, like you mentioned with potassium.
Since she's been drinking so much, she might be using up nutrients faster than usual. I'd consider giving her a good flush with some pH-balanced water to clear out any excess salts or buildup in the soil, then maybe hit her with a balanced nutrient solution to see if that helps. (Check the EC/PPM of the runoff to monitor for any salt buildup)
Keep an eye on her and see how she responds. Plants can be tricky sometimes, but with a little TLC, she'll hopefully bounce back.
Good luck, and happy growing! πΏπ₯