I just started having warping issues last night to on my newly P1S.
I first used the Bambu Lab Basic PLA which was delivered with my printer, on it’s standard presets. This worked great for me.
And it especially had great adhesion with the textured PEI buildplate. I was actually verry impressed first.
Then I started using PETG from Jayo. Which even stuck much better on the buildplate and I needed to get of the buildblate and knick it a bit to be able to get the prints off.
So I got more confident going to print greater projects. Last night I left a Panda Touch mount print overnight. And it had terrible warping this morning when I saw it… Just lost a bunch of filament, power consumption and time here…