STM32 RS485 Shield Fix

I have an STM32-based shield whose RS-485 channel works fine on a single drop, yet the moment several devices share the same daisy-chained cable the bus starts losing or corrupting bytes. The issue is... (Budget: ₹1500 - ₹12500 INR, Jobs: Circuit Design, Electronics, Embedded Systems, Microcontroller, PCB Layout, Schematic Review, STM32, Technical Documentation)