I assume you mean that you were shocked by the "low" measured speed compared to the Triax's IBO rating of 343 fps. Possible explanations include:
• Arrow weight: IBO rating is based on a 350 gn arrow. Most bows lose 1 fps per 4-5 gn of arrow weight, so 7-9 fps can be attributed to your arrow weight.
• Draw length: IBO rating is based on a 30" DL. Rule of thumb is 10 fps loss per inch shorter DL.
• Draw weight: IBO rating is at 70 lbs. Rule of thumb is 2 fps loss per lb lower DW. Even if your limb bolts are bottomed out, actual peak DW can vary a few lbs if string/cable lengths are a little out of spec. Have your shop measure your DW with a scale if you're curious.
• Extra string weight: IBO rating is based on a bare string. Peep sight, D-loop, silencers, etc. slow your string down a bit. I don't know a rule of thumb for fps loss per gn of extra string weight, but I think it would be a minor effect compared to those previously mentioned.
Regardless of what the chrono says, your bow delivers plenty of energy to kill whatever you want. I'm personally in the heavy arrow/speed-be-damned camp, so I'd recommend adding 100-200 gn to your arrow depending on what you're hunting, but there's more than one school of thought out there.