NTLM Machine Account Issues - APM

Good afternoon - I am hoping someone can point me in the right direction. I'm trying to use the iApp to deploy RDP Gateway using APM (using this template - ). Part of the config is to create a new NTLM Machine account. I had no issues creating the account - and the iApp deployment went swimmingly well. I also verified that the machine account showed up in AD as a computer account. However, I am seeing these errors in the APM logs:

May 15 17:40:32 f5lab debug nlad[6379]: 01620000:7: <0x56900b70> nlclnt[2a8e2c794]: is now initializing.
May 15 17:40:32 f5lab debug nlad[6379]: 01620000:7: <0x56900b70> NLAD_TRACE: cli_full_connection(output_cli = (nil), my_name = "F5LAB", dest_host = "domaincontroller.domain.local", port = 445, service = "IPC$", service_type = "IPC", user = "F5LAB$", domain = "DOMAIN")
May 15 17:40:32 f5lab debug nlad[6379]: 01620000:7: <0x56900b70> NLAD_TRACE: cli_full_connection(output_cli = (nil)) = 0xC000006D
May 15 17:40:32 f5lab err nlad[6379]: 01620000:3: <0x56900b70> nlclnt[2a8e2c794] init: Error [0xc000006d,NT_STATUS_LOGON_FAILURE] connecting to DC 10.11.12.13

I also cannot renew the NTLM account password from the GUI as I get this error:

Could not connect to domain domain controller of realm 'domain.local'
machine account update for 'f5lab' failed: Preauthentication failed, principal name: f5lab@domain.local. Invalid user credentials. (-1765328360)

I'm running on 12.1.3.4 and have tried the following:

• Recreated the NTLM account, multiple times. I know I have permissions as the account does show up in AD, and I do have domain admin level permissions
• Restarted the eca service (bigstart restart eca)
• Restarted the nlad service (bigstart restart nlad)
• Restarted the F5 appliance itself.
• Verified that the DNS settings are configured properly. The F5 is able to resolve the domain controller IP from the alias.
• No firewall exists between this F5 and the domain controller.

Has anyone seen this and if so - can anyone point me in the right direction? I thought I'd try here before opening a support ticket with F5.