I noticed some changes to sold prices recently. Notably where an offer was accepted on a BIN item, eBay no longer shows it as selling for full price (which is good). However, there seems to be a bug where a listing was offered both for auction and with a buy-it-now price, and it was sold at the BIN price or at a best offer price. These listings seem to be showing as sold for the minimum bid price. I've seen this on a listing I actually bought - it was offered with a minimum bid of $75, but also for a higher BIN price, and accepted offers. I made an offer, the seller counter-offered, and I accepted the counter; the price was higher than $75, but the listing now shows as sold for $75, both through the web UI and the API.
I have seen several other listings with suspiciously low 'sold' prices that show a bid count of 1, which I think are the same. e.g. https://www.ebay.com/itm/254909484188 .