Air conditioning problems A5

Air conditioning issue Audi A5 2010 - My A/C doesnt turn on immediately after starting the car. But once it starts it work great - Its not a Freon issue as I got that checked up

Coming to how to get that started - I have to accelerate to like 60-70 mph for a couple of mins and then the A/C starts working. Also note that just parking it and hitting on the accelerator does not work - Its like I have to force the air to trigger the A/C

Any suggestions or pointers would be helpful before I take it to a local shop