Need help identifying problem with new Ender 3 printer

I levelled the bed with the paper technique and everything seems to work fine - tiny bit of resistance in each corner and in the centre. But once I start attempting to print an actual model, the nozzle seems to be catching on the pla and moving the layers along with it but I'm still not entirely sure what's going on and need a second look at it to figure out what to do next. I could also make a video on what starts to happen over time and include it in this thread if anyone specifies...

This was supposed to be the outline of an oval model:

After I do the paper test I run a few quick test prints and adjust the z offset up or down as needed to get the first layer to stick well. If you have installed your own version of marlin consider enabling baby stepping so you can adjust it on the fly.

do you heat the nozzle during bed levelling ?

Yep, I heat the nozzle to 65 c and the bed to 55 c but the problem is that the piece of paper I use deforms very easily from the constant sliding underneath of the metal nozzle and so it's just a never ending cycle of adjusting each and every corner for hours and hours on end and no results to show for it. If anyone can link me to thin pieces of paper / plastic that won't deform as easily I would be very grateful.

then you're making the calibrtation too tight. The paper should slide fairly easily. you should feel the nozzle, but it should not be tight.

I usually use 90gsm paper. Standard is 80, the slight extra thickness seems to help.
Fine tuning is done by adjusting the 2-gap in the slicer.