1) upload activity
2) Wait the usual random time for the totals to update
3) Check the reports and see that the activity is included
4) Change the activity type to "hiking"
5) Wait for update
6) Check reports and see that the activity is no longer included in the report. E.g., if it was the only activity for a given day, report activities now shows 0 activities on that day.
It has been like this for at least two weeks. Probably longer but I have not recorded any hikes for quite a while previous to two weeks ago. I don't know if it is only hiking that is affected but the other activities I do (cycling, walking, inline skating) are fine. Running works fine too. That is the activity type I use on the device to record my hikes. I change to hiking after uploading.