We may have talked about this when it first happened, but SF banned city govt from doing business with like 30 states that didn't align with their values. Their hubris was such that they thought those states would fold for the honor of doing business with SF. Didn't work out that way.
Not only that, but the businesses that SF COULD do business with knew they had a captive audience and charged them accordingly. Hence the million dollar public restroom (quantity 1) debacle of around a year ago. They could have bought a cheap modular one, but the company was in Nevada - a state banned from doing business with SF. During the ban, they ended up making over 500 "special dispensation" exceptions just so the city could continue to function, but that wasn't enough.
Hence, the ban has now sort of ended. They are now allowed to do business in all 50 states, but only with businesses that align with SF values. Below is a 5 minute video by ABC San Francisco which fairly unbiasedly lays out the whole debacle.
https://youtu.be/1kZBD9xoQRQ