i first encountered this issue in june 2022. in my case it's eur.usd 5s realtime bars. prices are rounded to 0.00005 increments. around that time i also reported it for the first time to ib support. currency pairs that have only 3 decimals (like usd.jpy) don't suffer with this issue. tick data of eur.usd have precision 0.00001 so that is fine. iirc i didn't check historical bars. anyway, wrt the report to ib, few months back i reported it again, there were some contradicting information from ib about whether it's a bug or a feature (?), but last week i got an info from an ib support rep that the issue has been passed to the correct team now. that's the latest info i have so far.
