I agree with Bill above. Everything is good to go.
A battery being discharged shows lower terminal voltage than with no load. The more current being drawn, the lower the voltage will be. When the high current stops, the voltage will slowly rise.
The static voltage tables only apply when there is no current being drawn and the battery has not been charging for a few hours.
So you have one voltage behavior when discharging. You have another when charging, and a third when in static state.
These links can help you understand if you have time and inclination to study.
Battery University https://batteryuniversity.com/
How does the Lead Acid Battery Work?
https://batteryuniversity.com/learn/...ased_batteries
Charging lead acid batteries
https://batteryuniversity.com/learn/...d_acid_battery
How to Charge and When to Charge?
https://batteryuniversity.com/learn/...o_charge_table
How to Store Batteries
https://batteryuniversity.com/learn/...tore_batteries
Summary of Do’s and Don’ts
https://batteryuniversity.com/learn/..._battery_table
Confusion with Voltages
https://batteryuniversity.com/learn/..._with_voltages
How to Measure State-of-charge
https://batteryuniversity.com/learn/...tate_of_charge
I wish you good luck and happy trails ahead!