overall it sounds like it still needs to be correctly adjusted for creep,
and as for when first starting and making noise/sounding under strain,
how cold is it when your doing this, if cold as in near freezing or colder
it could be thicker fluid causing strain on system, things need to warm up to flow right
this is why most folks with machines in winter time, let them idle a while to get up to more normal temps on things before starting to work them!
also, I know t you stated the dealer replaced pump, BUT did they also drain hydraulic system and replace with NEW fluid? , as I think would need YOU to tell them you want this done at time of service, as , there is a LOT of fluid and thus added costs, so they will NOT do without your permission , but odds are you should have if you didn;t!, IMO< due to well if you had pump failure, and I have no clue how yours failed, but if it went really bad, and seals or other parts came apart, they could get pushed into the system and else where
so, I typically would flush system and start a new with new fluid and filter/s , peace of mind is nice and new fluid is never a bad thing! IMO
as if fluid is OLD< or worse has some water in it, or other things, it can also be causing flow issues!
LASTLY as for starting COLD< and creeping. does this machine have a HI idle option on cold starts/temps?
some do, and in HIGH idle, it would maybe be more prone to cause the creep when not adjusted correctly!
so it still seems to be an overall creeping issue, from not being adjusted correctly to me!
I'd be talking to your dealer about this stuff, it shouldn;t have been given back to you not adjusted correctly, and should not be charging more to correct there poor/incomplete repair on adjusting correctly
as for fluid and filters, thats your call on if you want them to drain and refill/replace filter, or you do it, but I would seriously consider it being done(pending on how old or??