VPN(SSL or IPSEC) becomes slow or unresponsive with UTM services turned on (1500D)

Hi,

still doing some testing and configuration on my new 1500D's but came across this problem when connecting to either of the VPN types and UTM services turned on outbound. If I have either AV/WF/WAF turned on and I try to access a website, it simply turns and turns until it eventually times out. I can have DF, IPS,App turned on and it doesn't seem to affect the performance I get from doing a speedtest. If the others are turned on, I simply can't reach the speedtest website. On average, I am getting 50mbps down and up which to me also seems slow, but I'd like to know what is going on with UTM first before working on throughput performance.

I mostly use the defaults of each category for now, except minor changes like for example P2P traffic being blocked by running the High_security profile instead of Default. 

Is it not recommended to turn on UTM on an outbound VPN session through a Fortigate or is it simply a bad configuration on my end. What would be the best way to diagnose the issue that "hangs" pages from loading when they are turned on?

Since this unit is still in testing, I haven't had much chance to test out regular internal traffic with the same UTM services to see if the same behavior occurs. I have been mostly working on the VPN recently. Any insight or testing mecanism anyone might have would be much appreciated. 

Thanks,

Ben