Charging issue

That is normal operation. Actually the charging speed begins to slow down significantly when the charging point reaches 80% and then even slower when it reaches 90%. This is optimized battery charging to protect the longevity of the battery and its function.

You can turn Optimized Battery Charging OFF if you want one charing speed throughout.

Axel F.

He already told you, if you have Optimized Charging turned on then turn it off. Go to Settings > General > Battery > Health and turn off optimized charging.

Note that you charging will still slow down when it reaches 80%.

You have an option to do nothing and accept the Optimize Battery Charging feature, as mentioned above, OR you can turn that feature OFF by Opening Settings ➔ Battery ➔ Battery Health ➔ Optimized Battery Charging: Set this to OFF.

Axel F.

Turn off Optimize Charging.

You should never have to restart the iPhone after 95%. Let the iPhone continue its charging process all the way up to 100% if you want to.

Axel F.