Johoes mempool (https://core.jochen-hoenicke.de/queue/#2h) only has about ~0.25 MB of transactions at or above 5 sat/b
Still if you are want get the confirmation on the average 30 minutes to 6 hours also you need to get confirmation on 2 blocks. Then how this 5sat/B or 8sat/B will be enough buddy?
I have seen that mempool is empty but required fees is cheap or economy.
You cannot expect the confirmation. 1 blocks confirmation maximum takes 26 days. May he need to wait till that time.
I have a hard time following your question... But just to clarify the current situation:
At THIS moment, my node (running for several weeks) estimates the following fees:
95% chance of getting your transaction into the next 3 blocks (~30 minutes) = 7 satoshi's/byte
95% chance of getting your transaction into the next 6 blocks (~1 hour) = 6 satoshi's/byte
95% chance of getting your transaction into the next 12 blocks (~2 hours) = 4 satoshi's/byte
95% chance of getting your transaction into the next 24 blocks (~4 hours) = 4 satoshi's/byte