I was able to determine that the increase you noticed in tick volume on Trading Station has to do with a recent change in how the platform counts it.
Previously, a new quote received by the platform would only count towards the tick volume, if the price had changed. Now, every quote received by the platform counts towards the tick volume, even if the price is the same as the previous quote.
For example, suppose the last bid price received on Trading Station for EUR/USD was 1.37843. Even if the next quote is still for 1.37843, that will count towards the tick volume now, where it wouldn't have in the past. This is more in line with how other platforms count tick volume including MT4.