You should be getting on average 1 staking reward per 1000 RADS you are staking per day. I stress the word average. Give time for your UTXOs to split appropriately and you should slowly start to see a convergence towards that rate.
i have almost 2k rads and rarely stake twice a day and often get full days between staking. wallet is left open for at least 12 hours a day. since 10/9, the wallet has only staked twice a day 4 times and missed 7 days