Site-to-Site VPN, UTM to SonicWall, Connection made but no traffic

Question

Welcome to my nightmare. 
 
 On-site UTM, remote office SonicWall. Before turning on VPN for the entire remote network, I tried to set up just a single host on the same LAN which navigates IPSec phase 1&2 successfully. The connection is up, but no traffic is being exchanged. 
 UTM local host is 10.242.3.222 SonicWall local host is 192.168.168.222

And on the SonicWall:

However I have had it configured at one point to be sending through this gateway where the packets and bytes out increment, though there is no receive traffic back. 
 
 EDIT to show NAT configuration:

NAT translation is enabled for both hosts. I have tried manually setting up every NAT and routing configuration I can think of, but no doubt there's something I'm missing since it's connected but can't communicate. 
 
 I will keep messing about with the NAT and routing configurations, but does it appear I've at least set up the LAN networks correctly for an individual host? I have to have, because it wouldn't connect otherwise, right?

Robert Yount · Accepted Answer

I have a few Sonicwall connections. I have never had to setup a NAT rule. Some differences I notice between our configs in the UTM. 
 Remote Gateway - I don't have MTU discovery or ECN enabled. 
 Connections - I have strict routing enabled.

Robert Yount · Answer

Bind tunnel to local interface doesn't show if strict routing is enabled. I always had issues if strict routing isn't enabled. I am connecting to 3 different Sonicwalls and have strict routing enabled on all of them. Make sure the hosts are pingable, run a ping from each side and check the firewall logs to make sure it's not an issue there. SW always adds the rule automatically as will the UTM if auto firewall rule is selected.

Bobby Tables · Answer

Yes, sorry for the confusion. If it's frustrating to someone who knows the network, I can't imagine your frustration coming in cold. Thanks again btw. 
 I seem to have gotten it figured, if only by bashing my keyboard in random sequence. As mentioned in my last post, I told my SonicWall to forward literally all traffic through the VPN for the 192.168.168.222 remote host. That along with masquerading and DNAT rules on the UTM side allow me to ping the UTM remotely, as well as browse the internet through the VPN tunnel. 
 The rest of the problems I have, such as failing to ping DCs let alone use them for credential authentication (no logon servers available) are likely due to another misconfiguration I should be able to sort out. 
 
 Thanks 1000x for your time. I will post back if I run into more tunneling problems, which I probably will. 
 
 EDIT: I have remedied the remaining communication issues by following your original recommendation of disabling NAT traversal options on both appliances. Though as I said the above NAT rules are in place manually. 
 
 And I hope I haven't used the "sugged as an answer" incorrectly. The above configuration options seem to have resolved my issues.