I run with 1.2mm retraction length. Increasing it did the trick for clean prints.
And I know it’s becoming a meme, but make sure your filament is absolutely dry. TPU is very runny and any bubbles will make it much worse. Also because TPU prints slower I decreased the seam gap to 3% and made it random and it turns out pretty good (also to make it more watertight which helps with the TPU feel when squishing stuff :))