Wyse 5070 Intermittent M.2 SATA detection at boot

Hello,

Been having an issue with some Dell Wyse 5070 units where they seem to be intermittently detecting the M.2 SATA drive when they boot up. All of the units are the same where the default drive was replaced with a Micron M500 480GB M.2 SATA drive. Typically the temporary fix is pressing F2 to enter the BIOS (where the drive is still not showing) then pressing exit and once the PC reboots then the drive is detected and Windows loads fine. So far I've tried updating the BIOS to the latest version, but that doesn't seem to have fixed the issue. Secure boot and UEFI boot are currently enabled.