@prap4trading The code looks fine to me. I played with scans for high volume breakouts last year and I would recommend a few things. I'd share what I created but I nuked it when I switched from day trading to swing trading.
Don't look for a single bar with high volume. Most of the signals you'll get will be worthless -- a single big order that hit a low volume stock and then nothing else happened. Instead, look for 2 or more consecutive bars. Reduce the time period if you're worried about how late that brings you to the party (3m instead of 5m).
Add a price component. True Range some multiple of Average True Range on the same bars as the increased volume. Or even ATR(3) > ATR()*3 or something like that to make the code simple.
I'd also recommend using the 3 minute timeframe due to the general understanding around the ThinkOrSwim community that 3 minutes is the soonest TOS servers will refresh your scan results.
Lastly, while you're testing/tweaking it helps to set an alert on the scan to email you when a symbol is added to the results. That way when you're finished trading for the day you can look at all of them to identify any adjustments you want to make. The email timestamps will tell you what times to look at on the charts.