Do you have a link handy? I had trouble with an e-ink board from them that drew tens of milliamps when it was asleep (on a well optimized ESP-32 it should be more like dozens of microamps)
You might be able to fix your existing boards if you look at the schematic and remove any unnecessary draws (voltage measurement dividers and always on LEDs are a good place to start). To get into the <20uA range the board needs to have an LDO with a low quiescent draw though, and designed so you can shut down power to the eink driver.