Tested with FTD 7.7.10-5. Firepower 1010 web managed by Firewall Device Manager. VTI route based VPN not possible to setup since BGP cannot be configured. For Policy based VPN setup, Parameters, PSKs, IPs, IKE policy, IPsec proposal, NAT, and ACL were quadruple checked, connection is never established. AWS and FDM do not detail why the connection failed so not possible to troubleshoot. In case anyone mentions FMC, I cannot get it, nor do I have the hardware for it. Probably won't work either anyway.
Regards.