case.setup reset required with esp. why?

hkershaw@derecho5:/glade/work/hkershaw/crocodile_dec2025/cases/da-mom6-test.0010(da-mom6-test.0010)$ ./case.submit 
Detected diff in locked file 'env_mach_pes.xml'
	'NTASKS_ESP' has changed from 1 to 896
ERROR: For your changes to take effect, run:
./case.setup --reset