Incorrect volume

I am curious about what could cause the volume traded of a stock to be incorrect. Hoping someone could read below and advise.

Opening share price is 11 cents. It dropped to 10.5 cents on a volume of 38000. A few minutes later there was a bid of 3000 at 11 cents and ask of 38000 at 11.5 cents.

1. I bought 33 shares at 11.5 cents which reflected in the volume although the share price remained at 10.5 cents. The volume increased from 38000 to 38033
2. Then I bought 930 shares at 11.5 cents to see what happens, again no change in the share price as it remained at 10.5 cents but this time the volume didn't change. It remained at 38033.
3. So I sold the 930 shares at 11 cents, again the share price still remained at 10.5 cents and the volume didn't change. I don't understand how the volume remained at 38033 when it should be at 39893.
4. All this time, the bid and ask mentioned above did not change. So then about an hour later I bought the entire bid portion of 3000 for 11 cents. The volume now updated to 41033 and the share price changed to 11 cents.

I know the share price doesn't always reflect the last price shares traded at but I thought the volume should always reflect any buying and selling. This is weird. Can someone advise if this is normal where the volume can go missing and what could be causing it.

Incorrect volume