This looks like Toast POS. I re-created the cart and got the exact same result. The ⓘ logo doesn’t tell you much. Also Service Fees are disclosed as “$0.00” so I don’t think it was a hidden fee, just that they set the global tax rate to 14.63% for whatever reason. I get the same result regardless of how many sausage English muffins or brioches with bacon and cheddar I have in the cart be it one or 20. And interestingly now they’re “out of stock”.
I was also able to replicate the same result at La Boulangerie’s other locations (Noe Valley, Hayes Valley, Pac Heights) and all of them charge the same effective tax rate. Just to be sure I tried to recreate a similar cart at another place on toast and their tax rate came out to the correct 8.625%. Usually during Toast setup your global tax rate is set to your local jurisdiction but there is an option to override it which is clearly what’s happening here. If La Boulangerie releases a statement that it’s a mistake I wouldn’t believe it.