It unfortunately has made me lower my expectations on candidate attendance to the point I schedule them closer together and slightly overlapping at times to make sure the hours I set aside for interviews are allocated efficiently

You probably need to use a PD charger (power delivery). If you have android USB C chargers, use ones that phones have “fast charging” or USB c chargers for laptops. The key here is that the wattage is too low on the phone chargers you’re using. I can charge my square terminals slowly with 10w chargers, the standard 5w from a computer won’t do. Shoot for 18w or above to use less power than the charging rate. Good luck!