Prior to Chrome 111, there was an issue where a frame could be generated by the browser, but not actually displayed, but would still be marked as the first contenful paint. This could happen in a number of ways, but was particularly problematic when the actual first paint was being delayed due to paint holding. With Chrome 111, this issue has been corrected.
At the same time, we discovered that some of the other cases where the frame was being held back were in fact unnecessary. This has also been fixed in Chrome 111, so we are now often displaying the first paint earlier than in previous releases.
Chrome will now report FCP as the time that the first contentful frame is actually presented to the user. This may result in FCP times increasing, and potentially LCP, if the first contentful paint also includes the LCP element. However, the effect of this is mitigated by the fact that we are showing that first frame earlier than before, so the net effect to users is a faster page load time.
Paint holding launched in Chrome 76, and FCP was reported early until these changes, which were included in Chrome 111.