Using "shapes" pieces and blindfold mode = sandbagging?

Apparently you are not allowed to play blindfold or use weird pieces, because if you do you are "artificially deflating your rating". I saw there was a Titled Arena warm up so I joined it, and obviously I decided to not use blindfold mode or weird pieces because I wanted the chance to play titled players. After a while I got kicked from the tournament and instantly banned. Lichess mods clearly thought I was cheating because they took the time to computer analyze over 10 of my games. They must have been mad I wasn't cheating, because I got banned for deflating my rating despite my profile saying I many times use blindfold mode.

Why offer crazy looking pieces or blindfold mode if you are not allowed to use them? Seems pretty stupid, especially because they ban you so quickly with no evidence.

You should have another account for blindfold, as playing blindfolded decreases your rating therefore it is much below your real skill, which unfortunately is sandbagging although you did not intend to

yeah, make an alt. that said, I would like to see lichess add blindfold as a variant instead of as an option

Lichess won't ban you for making a blindfold alt account. While the rules say multi-account is forbidden, there is a wide tolerance for situations where the alt-account is used for a different purpose than the main, like blindfold or weird openings. What's completely off-limit is playing fake games between two of your own accounts to manipulate rating.

These pieces and blindfold means that you play horribly so the algorithm thinks that you are sandbagging. You should have created an alt for blindfold.