Hello, @philchu128,
there is similar problem with make command while compiling preloader and U-Boot at Windows 10 via Embedded Command Shell (Cygwin) due to existence of independent and a bit different instance of make at Windows Linux Subsystem. It was discussed here: Preloader Compiling Error in Windows 10.
Try to not simple call ‘make’ but ‘/bin/make’. If it solve Your problem, You could then adjust default PATH variable of Embedded Command Shell as described at the linked thread above and everything would be OK.
I am not sure this would solve Your problem but worth to try.
Yours sincerelly
Jan Konečný.