Transitioning to the MCU ONLY state from the ACTIVE state, requires configuring the I2C_7 trigger before changing the NSLEEP bits. The configuration must be consistent between both PMICs.

Write 0x48:0x85:0x80:0x7F    // Set I2C_7 Trigger on TPS6594141B
Write 0x4C:0x85:0x80:0x7F    // Set I2C_7 Trigger on LP876441B1
Write 0x48:0x86:0x02:0xFC    // Set NSLEEP2 to trigger TO_MCU power sequence

Instead of writing to the NSLEEP bits to return to the ACTIVE state, it is also possible to use the WKUP1 pin on GPIO4 or GPIO10 to return the PMIC to the ACTIVE state.