If you using multiple IPSec profiles, you may run into multiple issues.
Changing tunnel protection without rebooting: Follow sequence
interface tunnel 20
shut
exit
!
interface tunnel 20
no tunnel protection ipsec profile DMVPN_IPS shared
exit
!
interface tunnel 20
no shut
!
end
Showing ISAKMP SA
show crypto isakmp sa
Clearing ISAKMP
clear crypto isakmp 1004
Confirming changes:
show dmvpn detail