Transmission problem?

I have a 2005 Outback, when the engine is cold it has difficulty shifting up (disengages the gear, RPMs go high, then shifts abruptly). But as soon as it warms up for 1-2 minutes, it shifts smoothly all day. What's going on?

Once your transmission is at operating temperature, check the fluid level.
Could also be a plugged screen.
A transmission oil change and filter replacement might be worth a try.
But check the oil level first.

I checked the levels cold at at operating temp, they're fine. It had a recent fluid change. Think it may be the filter or screen?

Did it work before the fluid change?
Then may have messed it up or forgot to replace the screen?
If it started just after they worked on it focus there.

I just bought it, and checked with the dealer and they changed the fluid and and filter. So I'm not sure if it did this before or not.