Windows 10 on 2019 model laptop running in ATA mode instead of AHCI
I think that there is some confusion : UDMA does not conflict with AHCI. AHCI only conflicts with IDE or RAID.
Ultra DMA (UDMA) is an evolved version of Direct memory access (DMA). Both are methods used for transferring data from main memory to a device without passing it through the CPU. Without (U)DMA, the CPU would be occupied for the duration of data transfer, with horrible consequences for performance.
There is no conflict, and your device is likely functioning correctly. Native Command Queuing (NCQ) is usually automatically enabled, if supported by the device.