This is my guess too. I clean mine with soap and water and rince it in the sink. Like my dishes.

Maybe try with these settings (found elsewhere) : https://imgur.com/a/vGV9DV0

It seems like it’s the default TPU settings with these tweaks :

• Pressure advance to 0.018
• Density to 1.111
• Max volumetric speed to 2

Is your filament dry? With TPU, it’s the first time that I saw a drastic difference of print quality. I dry my TPU for 3 hours at 45°C each time before printing.