You guys should see on the transactions page if the stake has confirmed or not. My guess is your coins staked a block and just haven't confirmed yet. It usually takes a couple (to a few) hours for them to be available.
Is that due to less number of people staking?
No. This is how staking works. When you stake a block, your coins move over to the stake column and are unavailable until the block is confirmed (just like how you don't get your coins from a mining pool until like...120 blocks later). If this is indeed the case (and not some weird wallet issue), then you'll see this on the transactions page.