Hi
ral_raz716,
Please check if you're charging with the original charger, and check if fast charging works with new cables.
Please note that fast charging doesn't appear on lock screen immediately after charging. After you plug in your charger, wait for a few minutes and check if it shows fast charging.
Please also tell us if battery care is enabled in Mobile Manager>PowerMaster. Please check if disabling battery care improves the problem.
If the problem still appears, please tell us in which battery level fast charging appears/disappears, and tell us whether you're using the original charger.
Thank you
🙂