overexposure in PP 2025 despite changing settings

You aren't setting up your color management. Period.

Hokay ...

1. Lumetri panel Settings tab ... the tab named Settings. That's where all CM settings are found.
2. Display Color Management, auto detect log and auto tonemapping all set to on.
3. Now select the display space, the same as you expect to export to. Rec.709 or HLG.
4. Set the Lumetri scopes to the same space as your export space. Do your color and tonal work.
5. Use only export presets built for your display space.

If you're on a Mac, but only on Macs without Reference modes, you have an additional issue. As Apple stupidly chose to set the OS controlled display transform to gamma 1.96.

The long established, *required* display transform for Rec.709 video, is gamma 2.4. Which is used by all broadcast standard systems, PCs, Android, TVs, AND Macs with Reference modes set to HDTV.

Ain't no fix. You choose between looking as expected on Macs without Reference modes, and too dark everywhere else.

Or looking as expected everywhere *but* on Macs without Reference modes.

Set Viewing Gamma to 1.96/QuickTime, you get the first. Set to gamma 2.2/Web, for bright room grading, or gamma 2.4/Broadcast if grading in a dark room, you get the second result.