Which Arduino? Which Scheduler library?
This one appears to be what you used: Scheduler - Arduino Reference This only works on a SAM-based Arduino such as a Due.
Where did you get the HX711 library? This one: GitHub - bogde/HX711: An Arduino library to interface the Avia Semiconductor HX711 24-Bit Analog-to-Digital Converter (ADC) for Weight Scales. seems to actually know about the yield() function and should work properly with the above scheduler.