Weird lines and odd seam

Hi All.

Using P1S. I think its on about 200 hours. I have been printing these post boxes. Ive done about 15 of them and they are all ok. But now im getting this weird layering. Not sure how you would describe it. See pics. The seam seems particularly bad and feels weak and thin. I can literally flex the material in with my fingers.

Filament is PLA basic. Ive re-run the calibration and bed levelling. Tried a brand new reel of filament. Tried some different slicer settings. Manual and automatic supports.

Im a beginner with the machine so Im using pretty much everything default. One minute it was printing all good and now not.

Anyone got any ideas what the issue might be? I read somewhere to do a full calibration?
Any help much appreciated, i dont really know where to go next.

Many thanks.