have a 2006 buick lacross with 50k miles. I changed the transmission fluid/filter and now makes trans. whine. worse when cold, only light whine accelerating on highway. i changed fluid/filter again OEM specs, still whine? any ideas?

Was the fluid the brand and specs listed in the owner’s manual?

Are you sure it was filled to the correct (not too little or not too much) level?

I put in the specified amount of Valvoline Dextron 6 with a GM filter and the fluid is right on the correct dipstick mark when hot/level…