AC Issue - Clutch/Compressor...?

[Ozz]

Greetings,
I recently changed my AC condensor - it had a leak - and then had a reputible shop evacuate and recharge the AC system. I did not add any PAG oil when I changed the condensor so they added some.

The AC works great now but when the compressor first engages after the car sits awhile (during work or over night), there is a god awful noise for about 2 seconds. It's hard to describe but it isn't a squeal - more like the clutch is engaging and the compressor doesn't want to turn - like a growl/grinding noise. It drags down the engine rpm until it 'clears up' a couple seconds later.

I'm wondering if there might be too much oil in the system such that the compressor is hydro-locked at startup... never heard of such a thing happening but it just sounds like the compressor won't turn and is really taking a lot of power to get it going.
I guess it could be a compressor clutch issue - but it's fine the rest of the time. Once the problem clears out at start up, I can turn the ac off and on without any issue - until the car sits for several hours... and then it does it again.

Sure, I need to put my head under the hood and have someone else start the AC so I can see what's happening... it was 28 degrees when I got up today so I didn't think an AC test would be valid.

Has anyone else experienced anything like this?