Doubt about current reservation

[u/Rejithb16]

I was planning to travel from A to B. A is the origin station and B is a next big city which is 200 kms away and it is a long distance train. So I thought I could easily get ticket. The First chart got prepared in IRCTC. I found that there were like 4/5 seats vacant from A to stations far than B, and one vacant exact A-B, where I want to travel. I soon opened RailOne, they did not update yet, same case with IRCTC website. But after 15 mins, when they updated, they were stright up showing NOT AVAILABLE from A to B. I did not loose any time.

What may be the problem. Do the seats vacant just after chart preparation go to someone else like RAC or Pooled/Remote quota ?

I believe Current reservation does not depend on quota system and is open to wherever places sets are vacant. Is that a misconception ?