Not sure if anyone had the same issue as mine - recently we had an update for page names so I created a segment with both the new and old page names combined. However, under the same metrics, they are showing a huge difference for Bounce Rate and Average Time on Site.
New segment with both new and old page names
New and old page names separate
PS: segment is set up at Hit level, no filter is added
Please comment if you ever had the same issue and how should I fix it. Thanks a lot.
It's hard to say without digging in deeper to the data... but if the names changed, and this report is showing the same date range it's a bit hard to compare... What happens if you compare a previous "full week of data" (it can be whatever day to day you want, so long as it is entirely before the name change), and an equivalent "full week of data (starting and ending on the same days of the week" and compare the two... is the data still significantly off? (Depending on when your name change occurred, you could compare more than a week... I am just making an assumption that the change was fairly recent and week might be closest cycle you can reasonable compare, but of course, a longer time frame would help even out the spikes/valleys that can impact the calculations).
Comparing them in the way you have shown, where the date range looks like it includes before and after the value change, means that you are getting the average bounce rate for both values for that entire time frame... it probably isn't a valid comparison because the shorter range of the two (I'm guessing the new name) is far more volatile data due to lack of history (plus all the 0s that could be included in the bounce rate before/after the change could be impacting the individual calculations when broken out this way).
Those calculations might be influenced by your Unspecified settings in the table with the separate page names. Are you using a filter or fixed elements in that latter table? Try changing the Unspecified filter and compare the results.