My ac had the same problems.
It was not due to a lack of freon but rather
a lack of air flow to release the heat from the condenser.
My fix was to increase airflow. E fans.
There is a e fan thread started by Blown Ford.
Good thread. We use different controllers but it is a
good thread. The only reason I use a dc controller was my f5
burned up and could have started a fire. Smell of an electrical
fire caused me to go another route, along with the manufacturer
support telling me I was not the only one and controllers were
in redesign. Blown has had great success with his f5.